diff --git a/doc/index.html b/doc/index.html
index 069a2ac..ccd0fce 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -519,14 +519,14 @@ data-styled.g140[id="sc-global-kJtbWf1"]{content:"sc-global-kJtbWf1,"}/*!sc*/
           55.627 l 55.6165,55.627 -231.245496,231.24803 c -127.185,127.1864
           -231.5279,231.248 -231.873,231.248 -0.3451,0 -104.688,
           -104.0616 -231.873,-231.248 z
-        " fill="currentColor"></path></g></svg></div></div><div class="sc-pZOBi gLjwfD api-content"><div class="sc-AxhUy hwqXNm"><div class="sc-Axmtr iDPWIz"><div class="sc-AxhCb kwETCN api-info"><h1 class="sc-AxmLO sc-fznNTe jkAxhK">EXPMail<!-- --> <span>(<!-- -->0.1<!-- -->)</span></h1><p>Download OpenAPI specification:<a download="swagger.json" target="_blank" class="sc-fzobTh kGLuBd">Download</a></p><div class="sc-fzoant sc-fzoYHE dKbsyH"><div class="sc-fzqyvX fgjVef"><div class="sc-fzqKVi jaIDKH"><span class="sc-fzooss bIpphf">E-mail<!-- -->:<!-- --> <a href="mailto:support@kumi.systems">support@kumi.systems</a></span> <!-- --> <!-- --> </div></div></div><div class="sc-fzoant sc-fzoYHE dKbsyH" data-role="redoc-description"><p>A simple endpoint to send email messages</p>
+        " fill="currentColor"></path></g></svg></div></div><div class="sc-pZOBi gLjwfD api-content"><div class="sc-AxhUy hwqXNm"><div class="sc-Axmtr iDPWIz"><div class="sc-AxhCb kwETCN api-info"><h1 class="sc-AxmLO sc-fznNTe jkAxhK">EXPMail<!-- --> <span>(<!-- -->0.3<!-- -->)</span></h1><p>Download OpenAPI specification:<a download="swagger.json" target="_blank" class="sc-fzobTh kGLuBd">Download</a></p><div class="sc-fzoant sc-fzoYHE dKbsyH"><div class="sc-fzqyvX fgjVef"><div class="sc-fzqKVi jaIDKH"><span class="sc-fzooss bIpphf">E-mail<!-- -->:<!-- --> <a href="mailto:support@kumi.systems">support@kumi.systems</a></span> <!-- --> <!-- --> </div></div></div><div class="sc-fzoant sc-fzoYHE dKbsyH" data-role="redoc-description"><p>A simple endpoint to send email messages</p>
 </div></div></div></div><div id="tag/sending" data-section-id="tag/sending" class="sc-AxhUy hwqXNm"><div class="sc-Axmtr iDPWIz"><div class="sc-AxhCb kwETCN"><h1 class="sc-AxmLO jveiGz"><a class="sc-fznyAO itFEXV" href="#tag/sending"></a>sending</h1></div></div><div class="sc-AxhCb kVsQWt"><div class="sc-fzoant sc-fzoYHE dKbsyH redoc-markdown "><p>Sending out an email</p>
 </div></div></div><div id="operation/sendMail" data-section-id="operation/sendMail" class="sc-AxhUy bCAoMt"><div class="sc-Axmtr sc-prorn ljylvQ"><div class="sc-AxhCb kwETCN"><h2 class="sc-fzozJi iieAzF"><a class="sc-fznyAO itFEXV" href="#operation/sendMail"></a>Send out an email<!-- --> </h2><h5 class="sc-fzplWN kzCYbv">Request Body schema: <span class="sc-fzpkJw ezqAQI">application/json</span></h5><div class="sc-fzoant sc-fzoYHE dKbsyH"><p>Object defining the email message to be sent</p>
 </div><table class="sc-fznxsB dVKLZp"><tbody><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="subject"><span class="sc-fzoXzr jYkWkg"></span>subject</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>Subject of the email</p>
 </div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="html"><span class="sc-fzoXzr jYkWkg"></span>html</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>String containing the HTML content of the email. Takes precedence over <code>htmlurl</code> if provided. If both <code>html</code> and <code>text</code> or <code>texturl</code> are provided, will create a multi-part MIME message.</p>
-</div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="htmlurl"><span class="sc-fzoXzr jYkWkg"></span>htmlurl</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>String containing the URL to a file containing the HTML content of the email. Ignored (but still validated) if <code>html</code> if provided. If both <code>htmlurl</code> and <code>text</code> or <code>texturl</code> are provided, will create a multi-part MIME message.</p>
+</div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="htmlurl"><span class="sc-fzoXzr jYkWkg"></span>htmlurl</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>String containing the URL to a file containing the HTML content of the email. Ignored if <code>html</code> if provided. If both <code>htmlurl</code> and <code>text</code> or <code>texturl</code> are provided, will create a multi-part MIME message.</p>
 </div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="text"><span class="sc-fzoXzr jYkWkg"></span>text</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>String containing the plain text content of the email. Takes precedence over <code>texturl</code> if provided. If both <code>text</code> and <code>html</code> or <code>htmlurl</code> are provided, will create a multi-part MIME message.</p>
-</div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="texturl"><span class="sc-fzoXzr jYkWkg"></span>texturl</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>String containing the URL to a file containing the plain text content of the email. Ignored (but still validated) if <code>text</code> is provided. If both <code>texturl</code> and <code>html</code> or <code>htmlurl</code> are provided, will create a multi-part MIME message.</p>
+</div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="texturl"><span class="sc-fzoXzr jYkWkg"></span>texturl</td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>String containing the URL to a file containing the plain text content of the email. Ignored if <code>text</code> is provided. If both <code>texturl</code> and <code>html</code> or <code>htmlurl</code> are provided, will create a multi-part MIME message.</p>
 </div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV sc-fzokvW ilQYAU" kind="field" title="sender"><span class="sc-fzoXzr jYkWkg"></span><button aria-label="expand properties">sender<svg class="sc-fznKkj czpFYH" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg></button></td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">object</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p><code>Recipient</code> object to be used as &quot;From:&quot; address for the email</p>
 </div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV sc-fzokvW ilQYAU" kind="field" title="recipients"><span class="sc-fzoXzr jYkWkg"></span><button aria-label="expand properties">recipients<svg class="sc-fznKkj czpFYH" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg></button><div class="sc-fzoWqW sc-fzplgP chnCRo"> required </div></td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa">Array of </span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">objects</span><span class="sc-fzqzlV sc-fzoMdx klHALA"> (<!-- -->Recipient<!-- -->) </span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>Array of <code>Recipient</code> objects to be used as &quot;To:&quot; addresses for the email</p>
 </div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV sc-fzokvW ilQYAU" kind="field" title="ccs"><span class="sc-fzoXzr jYkWkg"></span><button aria-label="expand properties">ccs<svg class="sc-fznKkj czpFYH" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg></button></td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa">Array of </span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">objects</span><span class="sc-fzqzlV sc-fzoMdx klHALA"> (<!-- -->Recipient<!-- -->) </span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>Array of <code>Recipient</code> objects to be used as &quot;CC:&quot; addresses for the email</p>
@@ -535,9 +535,9 @@ data-styled.g140[id="sc-global-kJtbWf1"]{content:"sc-global-kJtbWf1,"}/*!sc*/
 </div></div></div></td></tr><tr><td class="sc-fzqBZW sc-fzoyAV sc-fzokvW ilQYAU" kind="field" title="placeholders"><span class="sc-fzoXzr jYkWkg"></span><button aria-label="expand properties">placeholders<svg class="sc-fznKkj czpFYH" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg></button></td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa">Array of </span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">objects</span><span class="sc-fzqzlV sc-fzoMdx klHALA"> (<!-- -->Placeholder<!-- -->) </span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>Array of <code>Placeholder</code> objects. Any occurrences of <code>{PLACEHOLDER_NAME}</code> (<code>name</code> in all caps enclosed with curly brackets) in the email&#39;s HTML or plain text will be replaced by <code>value</code>.</p>
 </div></div></div></td></tr><tr class="last undefined"><td class="sc-fzqBZW sc-fzoyAV ewSDWh" kind="field" title="key"><span class="sc-fzoXzr jYkWkg"></span>key<div class="sc-fzoWqW sc-fzplgP chnCRo"> required </div></td><td class="sc-fzoLag fNYEXC"><div><div><span class="sc-fzqzlV sc-fzqLLg ghLFqa"></span><span class="sc-fzqzlV sc-fzoxnE iMySHJ">string</span></div> <div><div class="sc-fzoant sc-fzoYHE eTVXpd"><p>API key to authenticate request with</p>
 </div></div></div></td></tr></tbody></table><div><h3 class="sc-pbIaG kfpsaT">Responses</h3><div><button class="sc-pJurq eyfSne"><svg class="sc-fznKkj fscamO" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg><strong>200<!-- --> </strong><span class="sc-fzpkqZ ebKPJY"><p>The request was received and processed.</p>
-</span></button></div></div></div><div class="sc-AxgMl sc-AxheI hkIgFQ"><div class="sc-oTbqq fJLoZr"><button class="sc-pjSSY ewatGX"><span type="post" class="sc-prOVx hObpXE http-verb post">post</span><span class="sc-paXsP bhaFYt">/sender.php</span><svg class="sc-fznKkj ejwrda" style="margin-right:-25px" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg></button><div aria-hidden="true" class="sc-qQmou laHEoQ"><div class="sc-qYiqT kPAzCv"><div class="sc-fzoant sc-fzoYHE eTVXpd"></div><div tabindex="0" role="button"><div class="sc-pAZqv cGlHkj"><span>https://expmail.kumi.live</span>/sender.php</div></div></div></div></div><div><h3 class="sc-fzpans lerNRm"> Request samples </h3><div class="sc-fznzOf jLdbSQ" data-tabs="true"><ul class="react-tabs__tab-list" role="tablist"><li class="react-tabs__tab react-tabs__tab--selected" role="tab" id="react-tabs-0" aria-selected="true" aria-disabled="false" aria-controls="react-tabs-1" tabindex="0">Payload</li></ul><div class="react-tabs__tab-panel react-tabs__tab-panel--selected" role="tabpanel" id="react-tabs-1" aria-labelledby="react-tabs-0"><div><div class="sc-fzpisO dBHtDj"><span class="sc-fzoVTD kNWQuy">Content type</span><div class="sc-fzoJus ixzWHz">application/json</div></div><div class="sc-fznXWL iZtsQe"><div class="sc-fzqMdD cDvkPr"><div class="sc-fzomME ldXyaM"><button><div class="sc-fznAgC jKdGWZ">Copy</div></button><button> Expand all </button><button> Collapse all </button></div><div class="sc-fzoant gGXDRA sc-fzowVh iKXZfK"><div class="redoc-json"><code><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable "><span class="property token string">"subject"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"html"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"htmlurl"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"text"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"texturl"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"sender"</span>: <div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"recipients"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"ccs"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"bccs"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"attachments"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"url"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"filename"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"placeholders"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"value"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"key"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></code></div></div></div></div></div></div></div></div><div><h3 class="sc-fzpans lerNRm"> Response samples </h3><div class="sc-fznzOf jLdbSQ" data-tabs="true"><ul class="react-tabs__tab-list" role="tablist"><li class="tab-success react-tabs__tab--selected" role="tab" id="react-tabs-2" aria-selected="true" aria-disabled="false" aria-controls="react-tabs-3" tabindex="0">200</li></ul><div class="react-tabs__tab-panel react-tabs__tab-panel--selected" role="tabpanel" id="react-tabs-3" aria-labelledby="react-tabs-2"><div><div class="sc-fzpisO dBHtDj"><span class="sc-fzoVTD kNWQuy">Content type</span><div class="sc-fzoJus ixzWHz">application/json</div></div><div class="sc-fznXWL iZtsQe"><div class="sc-fzqMdD cDvkPr"><div class="sc-fzomME ldXyaM"><button><div class="sc-fznAgC jKdGWZ">Copy</div></button><button> Expand all </button><button> Collapse all </button></div><div class="sc-fzoant gGXDRA sc-fzowVh iKXZfK"><div class="redoc-json"><code><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable "><span class="property token string">"status"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"error"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></code></div></div></div></div></div></div></div></div></div></div></div></div><div class="sc-oTNDV izusvA"></div></div></div>
+</span></button></div></div></div><div class="sc-AxgMl sc-AxheI hkIgFQ"><div class="sc-oTbqq fJLoZr"><button class="sc-pjSSY ewatGX"><span type="post" class="sc-prOVx hObpXE http-verb post">post</span><span class="sc-paXsP bhaFYt">/sender.php</span><svg class="sc-fznKkj ejwrda" style="margin-right:-25px" version="1.1" viewBox="0 0 24 24" x="0" xmlns="http://www.w3.org/2000/svg" y="0" aria-hidden="true"><polygon points="17.3 8.3 12 13.6 6.7 8.3 5.3 9.7 12 16.4 18.7 9.7 "></polygon></svg></button><div aria-hidden="true" class="sc-qQmou laHEoQ"><div class="sc-qYiqT kPAzCv"><div class="sc-fzoant sc-fzoYHE eTVXpd"></div><div tabindex="0" role="button"><div class="sc-pAZqv cGlHkj"><span>https://expmail.kumi.live</span>/sender.php</div></div></div></div></div><div><h3 class="sc-fzpans lerNRm"> Request samples </h3><div class="sc-fznzOf jLdbSQ" data-tabs="true"><ul class="react-tabs__tab-list" role="tablist"><li class="react-tabs__tab react-tabs__tab--selected" role="tab" id="react-tabs-0" aria-selected="true" aria-disabled="false" aria-controls="react-tabs-1" tabindex="0">Payload</li></ul><div class="react-tabs__tab-panel react-tabs__tab-panel--selected" role="tabpanel" id="react-tabs-1" aria-labelledby="react-tabs-0"><div><div class="sc-fzpisO dBHtDj"><span class="sc-fzoVTD kNWQuy">Content type</span><div class="sc-fzoJus ixzWHz">application/json</div></div><div class="sc-fznXWL iZtsQe"><div class="sc-fzqMdD cDvkPr"><div class="sc-fzomME ldXyaM"><button><div class="sc-fznAgC jKdGWZ">Copy</div></button><button> Expand all </button><button> Collapse all </button></div><div class="sc-fzoant gGXDRA sc-fzowVh iKXZfK"><div class="redoc-json"><code><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable "><span class="property token string">"subject"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"html"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"htmlurl"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"text"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"texturl"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"sender"</span>: <div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"recipients"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"ccs"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"bccs"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"email"</span>: <span class="token string">&quot;user@example.com&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"attachments"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"url"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"filename"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"cid"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"placeholders"</span>: <div class="collapser"></div><span class="token punctuation">[</span><span class="ellipsis"></span><ul class="array collapsible"><li><div class="hoverable collapsed"><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable collapsed"><span class="property token string">"name"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable collapsed"><span class="property token string">"value"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></div></li></ul><span class="token punctuation">]</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"key"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></code></div></div></div></div></div></div></div></div><div><h3 class="sc-fzpans lerNRm"> Response samples </h3><div class="sc-fznzOf jLdbSQ" data-tabs="true"><ul class="react-tabs__tab-list" role="tablist"><li class="tab-success react-tabs__tab--selected" role="tab" id="react-tabs-2" aria-selected="true" aria-disabled="false" aria-controls="react-tabs-3" tabindex="0">200</li></ul><div class="react-tabs__tab-panel react-tabs__tab-panel--selected" role="tabpanel" id="react-tabs-3" aria-labelledby="react-tabs-2"><div><div class="sc-fzpisO dBHtDj"><span class="sc-fzoVTD kNWQuy">Content type</span><div class="sc-fzoJus ixzWHz">application/json</div></div><div class="sc-fznXWL iZtsQe"><div class="sc-fzqMdD cDvkPr"><div class="sc-fzomME ldXyaM"><button><div class="sc-fznAgC jKdGWZ">Copy</div></button><button> Expand all </button><button> Collapse all </button></div><div class="sc-fzoant gGXDRA sc-fzowVh iKXZfK"><div class="redoc-json"><code><div class="collapser"></div><span class="token punctuation">{</span><span class="ellipsis"></span><ul class="obj collapsible"><li><div class="hoverable "><span class="property token string">"status"</span>: <span class="token string">&quot;string&quot;</span><span class="token punctuation">,</span></div></li><li><div class="hoverable "><span class="property token string">"error"</span>: <span class="token string">&quot;string&quot;</span></div></li></ul><span class="token punctuation">}</span></code></div></div></div></div></div></div></div></div></div></div></div></div><div class="sc-oTNDV izusvA"></div></div></div>
     <script>
-    const __redoc_state = {"menu":{"activeItemIdx":-1},"spec":{"data":{"openapi":"3.0.0","info":{"description":"A simple endpoint to send email messages","version":"0.1","title":"EXPMail","contact":{"email":"support@kumi.systems"}},"tags":[{"name":"sending","description":"Sending out an email"}],"paths":{"/sender.php":{"post":{"tags":["sending"],"summary":"Send out an email","operationId":"sendMail","requestBody":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/Mail"}}},"description":"Object defining the email message to be sent","required":true},"responses":{"200":{"description":"The request was received and processed.","content":{"application/json":{"schema":{"type":"object","properties":{"status":{"type":"string","description":"\"Success\" if message was successfully sent, else \"error\""},"error":{"type":"string","description":"Error message, only included if an error has occurred"}}}}}}}}}},"servers":[{"url":"https://expmail.kumi.live"}],"components":{"schemas":{"Placeholder":{"type":"object","required":["name"],"properties":{"name":{"type":"string","description":"Name of the placeholder - will be converted to ALL CAPS by the server if it isn't already"},"value":{"type":"string","description":"Value to insert into placeholder"}}},"Attachment":{"type":"object","required":["url"],"properties":{"url":{"type":"string","format":"url","description":"URL from where to fetch the file to attach"},"filename":{"type":"string","description":"File name to use for email attachment. If not set, defaults to name from Content-Disposition header of URL if it exists, else the base name of the URL."}}},"Recipient":{"type":"object","required":["email"],"properties":{"email":{"type":"string","format":"email","description":"Email address of the recipient"},"name":{"type":"string","description":"Name of the recipient"}}},"Mail":{"type":"object","required":["recipients","key"],"properties":{"subject":{"type":"string","description":"Subject of the email"},"html":{"type":"string","description":"String containing the HTML content of the email. Takes precedence over `htmlurl` if provided. If both `html` and `text` or `texturl` are provided, will create a multi-part MIME message."},"htmlurl":{"type":"string","description":"String containing the URL to a file containing the HTML content of the email. Ignored (but still validated) if `html` if provided. If both `htmlurl` and `text` or `texturl` are provided, will create a multi-part MIME message."},"text":{"type":"string","description":"String containing the plain text content of the email. Takes precedence over `texturl` if provided. If both `text` and `html` or `htmlurl` are provided, will create a multi-part MIME message."},"texturl":{"type":"string","description":"String containing the URL to a file containing the plain text content of the email. Ignored (but still validated) if `text` is provided. If both `texturl` and `html` or `htmlurl` are provided, will create a multi-part MIME message."},"sender":{"allOf":[{"description":"`Recipient` object to be used as \"From:\" address for the email"},{"$ref":"#/components/schemas/Recipient"}]},"recipients":{"type":"array","description":"Array of `Recipient` objects to be used as \"To:\" addresses for the email","items":{"$ref":"#/components/schemas/Recipient"}},"ccs":{"type":"array","description":"Array of `Recipient` objects to be used as \"CC:\" addresses for the email","items":{"$ref":"#/components/schemas/Recipient"}},"bccs":{"type":"array","description":"Array of `Recipient` objects to be used as \"BCC:\" addresses for the email","items":{"$ref":"#/components/schemas/Recipient"}},"attachments":{"type":"array","description":"Array of `Attachment` objects to be attached to the email","items":{"$ref":"#/components/schemas/Attachment"}},"placeholders":{"type":"array","description":"Array of `Placeholder` objects. Any occurrences of `{PLACEHOLDER_NAME}` (`name` in all caps enclosed with curly brackets) in the email's HTML or plain text will be replaced by `value`.","items":{"$ref":"#/components/schemas/Placeholder"}},"key":{"type":"string","description":"API key to authenticate request with"}}}}}}},"searchIndex":{"store":["tag/sending","operation/sendMail"],"index":{"version":"2.3.8","fields":["title","description"],"fieldVectors":[["title/0",[0,0.168]],["description/0",[0,0.095,1,0.129,2,0.129]],["title/1",[0,0.111,1,0.151,2,0.151]],["description/1",[]]],"invertedIndex":[["email",{"_index":2,"title":{"1":{}},"description":{"0":{}}}],["out",{"_index":1,"title":{"1":{}},"description":{"0":{}}}],["send",{"_index":0,"title":{"0":{},"1":{}},"description":{"0":{}}}]],"pipeline":[]}},"options":{}};
+    const __redoc_state = {"menu":{"activeItemIdx":-1},"spec":{"data":{"openapi":"3.0.0","info":{"description":"A simple endpoint to send email messages","version":"0.3","title":"EXPMail","contact":{"email":"support@kumi.systems"}},"tags":[{"name":"sending","description":"Sending out an email"}],"paths":{"/sender.php":{"post":{"tags":["sending"],"summary":"Send out an email","operationId":"sendMail","requestBody":{"content":{"application/json":{"schema":{"$ref":"#/components/schemas/Mail"}}},"description":"Object defining the email message to be sent","required":true},"responses":{"200":{"description":"The request was received and processed.","content":{"application/json":{"schema":{"type":"object","properties":{"status":{"type":"string","description":"\"Success\" if message was successfully sent, else \"error\""},"error":{"type":"string","description":"Error message, only included if an error has occurred"}}}}}}}}}},"servers":[{"url":"https://expmail.kumi.live"}],"components":{"schemas":{"Placeholder":{"type":"object","required":["name"],"properties":{"name":{"type":"string","description":"Name of the placeholder - will be converted to ALL CAPS by the server if it isn't already"},"value":{"type":"string","description":"Value to insert into placeholder"}}},"Attachment":{"type":"object","required":["url"],"properties":{"url":{"type":"string","format":"url","description":"URL from where to fetch the file to attach"},"filename":{"type":"string","description":"File name to use for email attachment. If not set, defaults to name from Content-Disposition header of URL if it exists, else the base name of the URL."},"cid":{"type":"string","description":"Content ID for the attachment, needed for embedded images - use something like `<img src=\"cid:YOUR_CID\">` in your HTML code"}}},"Recipient":{"type":"object","required":["email"],"properties":{"email":{"type":"string","format":"email","description":"Email address of the recipient"},"name":{"type":"string","description":"Name of the recipient"}}},"Mail":{"type":"object","required":["recipients","key"],"properties":{"subject":{"type":"string","description":"Subject of the email"},"html":{"type":"string","description":"String containing the HTML content of the email. Takes precedence over `htmlurl` if provided. If both `html` and `text` or `texturl` are provided, will create a multi-part MIME message."},"htmlurl":{"type":"string","description":"String containing the URL to a file containing the HTML content of the email. Ignored if `html` if provided. If both `htmlurl` and `text` or `texturl` are provided, will create a multi-part MIME message."},"text":{"type":"string","description":"String containing the plain text content of the email. Takes precedence over `texturl` if provided. If both `text` and `html` or `htmlurl` are provided, will create a multi-part MIME message."},"texturl":{"type":"string","description":"String containing the URL to a file containing the plain text content of the email. Ignored if `text` is provided. If both `texturl` and `html` or `htmlurl` are provided, will create a multi-part MIME message."},"sender":{"allOf":[{"description":"`Recipient` object to be used as \"From:\" address for the email"},{"$ref":"#/components/schemas/Recipient"}]},"recipients":{"type":"array","description":"Array of `Recipient` objects to be used as \"To:\" addresses for the email","items":{"$ref":"#/components/schemas/Recipient"}},"ccs":{"type":"array","description":"Array of `Recipient` objects to be used as \"CC:\" addresses for the email","items":{"$ref":"#/components/schemas/Recipient"}},"bccs":{"type":"array","description":"Array of `Recipient` objects to be used as \"BCC:\" addresses for the email","items":{"$ref":"#/components/schemas/Recipient"}},"attachments":{"type":"array","description":"Array of `Attachment` objects to be attached to the email","items":{"$ref":"#/components/schemas/Attachment"}},"placeholders":{"type":"array","description":"Array of `Placeholder` objects. Any occurrences of `{PLACEHOLDER_NAME}` (`name` in all caps enclosed with curly brackets) in the email's HTML or plain text will be replaced by `value`.","items":{"$ref":"#/components/schemas/Placeholder"}},"key":{"type":"string","description":"API key to authenticate request with"}}}}}}},"searchIndex":{"store":["tag/sending","operation/sendMail"],"index":{"version":"2.3.8","fields":["title","description"],"fieldVectors":[["title/0",[0,0.168]],["description/0",[0,0.095,1,0.129,2,0.129]],["title/1",[0,0.111,1,0.151,2,0.151]],["description/1",[]]],"invertedIndex":[["email",{"_index":2,"title":{"1":{}},"description":{"0":{}}}],["out",{"_index":1,"title":{"1":{}},"description":{"0":{}}}],["send",{"_index":0,"title":{"0":{},"1":{}},"description":{"0":{}}}]],"pipeline":[]}},"options":{}};
 
     var container = document.getElementById('redoc');
     Redoc.hydrate(__redoc_state, container);;
diff --git a/doc/swagger.yaml b/doc/swagger.yaml
index d5f2edd..a005175 100644
--- a/doc/swagger.yaml
+++ b/doc/swagger.yaml
@@ -1,7 +1,7 @@
 openapi: 3.0.0
 info:
   description: A simple endpoint to send email messages
-  version: '0.2'
+  version: '0.3'
   title: EXPMail
   contact:
     email: support@kumi.systems
@@ -63,6 +63,9 @@ components:
         filename:
           type: string
           description: 'File name to use for email attachment. If not set, defaults to name from Content-Disposition header of URL if it exists, else the base name of the URL.'
+        cid:
+          type: string
+          description: 'Content ID for the attachment, needed for embedded images - use something like `<img src="cid:YOUR_CID">` in your HTML code'
     Recipient:
       type: object
       required:
@@ -89,13 +92,13 @@ components:
           description: 'String containing the HTML content of the email. Takes precedence over `htmlurl` if provided. If both `html` and `text` or `texturl` are provided, will create a multi-part MIME message.'
         htmlurl:
           type: string
-          description: 'String containing the URL to a file containing the HTML content of the email. Ignored (but still validated) if `html` if provided. If both `htmlurl` and `text` or `texturl` are provided, will create a multi-part MIME message.'
+          description: 'String containing the URL to a file containing the HTML content of the email. Ignored if `html` if provided. If both `htmlurl` and `text` or `texturl` are provided, will create a multi-part MIME message.'
         text:
           type: string
           description: 'String containing the plain text content of the email. Takes precedence over `texturl` if provided. If both `text` and `html` or `htmlurl` are provided, will create a multi-part MIME message.'
         texturl:
           type: string
-          description: 'String containing the URL to a file containing the plain text content of the email. Ignored (but still validated) if `text` is provided. If both `texturl` and `html` or `htmlurl` are provided, will create a multi-part MIME message.'
+          description: 'String containing the URL to a file containing the plain text content of the email. Ignored if `text` is provided. If both `texturl` and `html` or `htmlurl` are provided, will create a multi-part MIME message.'
         sender:
           allOf:
             - description: '`Recipient` object to be used as "From:" address for the email'
diff --git a/helpers.php b/helpers.php
deleted file mode 100644
index 6f56e48..0000000
--- a/helpers.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-function getFilename($url){
-    $content = get_headers($url,1);
-    $content = array_change_key_case($content, CASE_LOWER);
-
-    if ($content['content-disposition']) {
-        $tmp_name = explode('=', $content['content-disposition']);
-        if ($tmp_name[1]) $realfilename = trim($tmp_name[1],'";\'');
-    } else  {
-        $stripped_url = preg_replace('/\\?.*/', '', $url);
-        $stripped_url = preg_replace('/\\/$/', '', $stripped_url);
-        $realfilename = basename($stripped_url);
-    } 
-
-    return $realfilename;
-}
-
-function checkURL($url) {
-    $url = filter_var($url, FILTER_SANITIZE_URL);
-    if (filter_var($url, FILTER_VALIDATE_URL) === FALSE || !in_array(strtolower(parse_url($url, PHP_URL_SCHEME)), ['http','https'], true)) return false;
-    $file_headers = @get_headers($url);
-    if ($httpStatus<400) return true;
-    return false;
-}
\ No newline at end of file
diff --git a/sender.php b/sender.php
index d2bea7d..5bb9294 100644
--- a/sender.php
+++ b/sender.php
@@ -2,7 +2,6 @@
 
 require_once 'vendor/autoload.php';
 require_once 'config.php';
-require_once 'helpers.php';
 require_once 'File.class.php';
 
 use PHPMailer\PHPMailer\PHPMailer;
@@ -17,11 +16,27 @@ try {
 
     if (!in_array($json["key"], $API_KEYS)) throw new Exception("Who are you?");
 
-    if ($json["htmlurl"] && !checkURL($json["htmlurl"])) throw new Exception("Your HTML URL isn't working.");
-    if ($json["texturl"] && !checkURL($json["texturl"])) throw new Exception("Your text URL isn't working.");
+    if ($json["html"]) {
+        $html = $json["html"];
+    } else if ($json["htmlurl"]) {
+        try {
+            $htmlfile = new File($json["htmlurl"]);
+            $html = $htmlfile->fetch_file();
+        } catch (\Exception $e) {
+            throw new Exception("Could not fetch URL for HTML message: " . $e->getMessage());
+        }
+    }
 
-    $html = ($json["html"] ? $json["html"] : ($json["htmlurl"] ? file_get_contents($json["htmlurl"]) : null));
-    $text = ($json["text"] ? $json["text"] : ($json["texturl"] ? file_get_contents($json["texturl"]) : null));
+    if ($json["text"]) {
+        $text = $json["text"];
+    } else if ($json["texturl"]) {
+        try {
+            $textfile = new File($json["texturl"]);
+            $text = $textfile->fetch_file();
+        } catch (\Exception $e) {
+            throw new Exception("Could not fetch URL for plain text message: " . $e->getMessage());
+        }
+    }
 
     foreach ($json["placeholders"] as $placeholder) {
         $html = str_replace("{".strtoupper($placeholder["name"])."}", $placeholder["value"], $html);
@@ -61,7 +76,8 @@ try {
         if ($file->get_status() >= 400) throw new Exception("Error downloading " . $attachment["url"] . " - Status: " . $file->get_status());
         $content = $file->fetch_file();
         $filename = ($attachment["filename"] ? $attachment["filename"] : $file->get_filename());
-        $mailer->addStringAttachment($content, $filename);
+        $cid = ($attachment["cid"] ? $attachment["cid"] : 0);
+        $mailer->addStringEmbeddedImage($content, $cid, $filename);
     }
 
     $mailer->send();