diff --git a/app/presenters/mail_presenter.rb b/app/presenters/mail_presenter.rb
index a320c1ce0..40070fd04 100644
--- a/app/presenters/mail_presenter.rb
+++ b/app/presenters/mail_presenter.rb
@@ -12,7 +12,7 @@ class MailPresenter < SimpleDelegator
   end
 
   def text_content
-    @decoded_text_content ||= encode_to_unicode(text_part&.body&.decoded || fallback_content)
+    @decoded_text_content ||= encode_to_unicode(text_part&.decoded || fallback_content)
     @text_content ||= {
       full: @decoded_text_content,
       reply: extract_reply(@decoded_text_content)[:reply],
@@ -21,7 +21,7 @@ class MailPresenter < SimpleDelegator
   end
 
   def html_content
-    @decoded_html_content ||= encode_to_unicode(html_part&.body&.decoded || fallback_content)
+    @decoded_html_content ||= encode_to_unicode(html_part&.decoded || fallback_content)
     @html_content ||= {
       full: @decoded_html_content,
       reply: extract_reply(@decoded_html_content)[:reply],
@@ -70,6 +70,8 @@ class MailPresenter < SimpleDelegator
   # forcing the encoding of the content to UTF-8 so as to be compatible with database and serializers
   def encode_to_unicode(str)
     current_encoding = str.encoding.name
+    return str if current_encoding == 'UTF-8'
+
     str.encode(current_encoding, 'UTF-8', invalid: :replace, undef: :replace, replace: '?')
   end