Hello everyone,
I have received several reports from users who are unable to view PDF attachments in their mailboxes. Upon reviewing the original emails, I verified that the base64-encoded document is present; however, the MIME header is defined as follows:
--------------5213CF2D7DCD003C0B2F3FF5
Content-Type: application/applefile;
name="23_MDT-DRTSPL-DGDA-2025-023-signed.pdf"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename="23_MDT-DRTSPL-DGDA-2025-023-signed.pdf"
It appears that the problem stems from the content type, as it is using application/applefile instead of application/pdf.
Here are the tests I performed:
-
I downloaded and decoded the base64 content, and the PDF displayed correctly, indicating that the file itself is not corrupted.
- When downloading the email as an .eml file from Carbonio's web interface and opening it in another client, the PDF attachment displays properly.
Furthermore, I modified the original email file directly in the user’s mailbox at a low level, changing the Content-Type to application/pdf. With this change, the PDF displays correctly, suggesting that Carbonio Mail does not correctly interpret files marked as application/applefile.
Has anyone else experienced this issue? If so, is there a known solution or patch that can be applied?
Thank you in advance.