diff --git a/app/models/incoming_message.rb b/app/models/incoming_message.rb
index d15d8bb950..84be9aec3a 100644
--- a/app/models/incoming_message.rb
+++ b/app/models/incoming_message.rb
@@ -462,6 +462,7 @@ def extract_attachments
     _mail = raw_email.mail!
     attachment_attributes = MailHandler.get_attachment_attributes(_mail)
     attachment_attributes = attachment_attributes.inject({}) do |memo, attrs|
+      attrs.delete(:body_without_headers)
       memo[attrs[:hexdigest]] = attrs
       memo
     end
diff --git a/lib/mail_handler/backends/mail_backend.rb b/lib/mail_handler/backends/mail_backend.rb
index f5904f835f..e26a20bfde 100644
--- a/lib/mail_handler/backends/mail_backend.rb
+++ b/lib/mail_handler/backends/mail_backend.rb
@@ -369,16 +369,19 @@ def get_attachment_attributes(mail)
 
           if leaf.within_rfc822_attachment
             within_rfc822_subject = get_within_rfc822_subject(leaf)
-            body = extract_attached_message_headers(leaf)
+            body_with_header = extract_attached_message_headers(leaf)
           end
 
-          leaf_attributes = { url_part_number: leaf.url_part_number,
-                              content_type: get_content_type(leaf),
-                              filename: get_part_file_name(leaf),
-                              charset: leaf.charset,
-                              within_rfc822_subject: within_rfc822_subject,
-                              body: body,
-                              hexdigest: Digest::MD5.hexdigest(body) }
+          {
+            url_part_number: leaf.url_part_number,
+            content_type: get_content_type(leaf),
+            filename: get_part_file_name(leaf),
+            charset: leaf.charset,
+            within_rfc822_subject: within_rfc822_subject,
+            body_without_headers: body,
+            body: body_with_header || body,
+            hexdigest: Digest::MD5.hexdigest(body_with_header || body)
+          }
         end
       end
 
@@ -397,21 +400,25 @@ def attempt_to_find_original_attachment_attributes(mail, body:, nested: false)
         all_attributes = get_attachment_attributes(mail)
 
         attributes = all_attributes.find do |attrs|
-          # ensure both bodies have the same line endings
+          # ensure bodies have the same line endings
           hexdigest_1 = Digest::MD5.hexdigest(
             Mail::Utilities.to_crlf(attrs[:body])
           )
           hexdigest_2 = Digest::MD5.hexdigest(
+            Mail::Utilities.to_crlf(attrs[:body_without_headers])
+          )
+          hexdigest_3 = Digest::MD5.hexdigest(
             Mail::Utilities.to_crlf(body)
           )
-          hexdigest_1 == hexdigest_2
+          hexdigest_1 == hexdigest_3 || hexdigest_2 == hexdigest_3
         end
 
         return attributes if nested
 
+        mail_body = Mail.new(body).body
         attributes ||= attempt_to_find_original_attachment_attributes(
-          mail, body: Mail.new(body).to_s, nested: true
-        )
+          mail, body: mail_body, nested: true
+        ) unless mail_body.empty?
 
         attributes
       end
diff --git a/spec/lib/mail_handler/backends/mail_backend_spec.rb b/spec/lib/mail_handler/backends/mail_backend_spec.rb
index 7a5143249b..9b888717bd 100644
--- a/spec/lib/mail_handler/backends/mail_backend_spec.rb
+++ b/spec/lib/mail_handler/backends/mail_backend_spec.rb
@@ -437,15 +437,16 @@
     let(:mail) do
       mail_attachment = Mail.new(
         <<~EML
-          Date: Tue, 08 Aug 2023 10:00:00 +0000
-          Message-ID: <64d611ca31906_ccf71e5039542@localhost>
+          Subject: Attached email
+
+          Hello world
         EML
       ).to_s
 
       Mail.new do
         add_file filename: 'crlf.txt', content: "foo\r\nfoo"
         add_file filename: 'lf.txt', content: "bar\nbar"
-        add_file filename: 'mail.txt', content: mail_attachment
+        add_file filename: 'mail.eml', content: mail_attachment
       end
     end
 
@@ -465,14 +466,15 @@
       it { is_expected.to include(body: "bar\nbar") }
     end
 
-    context 'when body missing leading zero on dates' do
+    context 'when attached email headers are different' do
       let(:body) do
         <<~EML
-          Date: Tue, 8 Aug 2023 10:00:00 +0000
-          Message-ID: <64d611ca31906_ccf71e5039542@localhost>
+          Subject: A different subject
+
+          Hello world
         EML
       end
-      it { expect(attributes[:body]).to include('08 Aug 2023') }
+      it { is_expected.to include(body_without_headers: "Hello world\n") }
     end
 
     context 'when body does not match' do
diff --git a/spec/lib/mail_handler/mail_handler_spec.rb b/spec/lib/mail_handler/mail_handler_spec.rb
index b3c43e371c..a07f6774a6 100644
--- a/spec/lib/mail_handler/mail_handler_spec.rb
+++ b/spec/lib/mail_handler/mail_handler_spec.rb
@@ -545,6 +545,7 @@ def expect_header_string(fixture_file, header, header_string)
     attributes.each_with_index do |attr, index|
       attr.delete(:charset)
       attr.delete(:body)
+      attr.delete(:body_without_headers)
       attr.delete(:hexdigest)
       expect(attr).to eq(expected_attributes[index])
     end