We recently discovered an issue with Zimbra when receiving attachments that were sent using Thunderbird, specifically text and picture files. All other attachments appear to work fine.

The problem is that when a message is sent from Thunderbird with either of the two file types as attachments, their are appended to the end of the message in Zimbra and are no longer attachments. Thunderbird does something similar where the contents of the files are appended to the end of the message, but they are still kept as attachments.

When sending from Zimbra, all attachments remain as attachments and aren't appended to the end of the email, and Thunderbird reads the email exactly the same as when the message is sent from it.

So I was wondering if anyone else has experienced this behaviour? If so were you able to find a solution? I couldn't turn anything up with searches unfortunately, though I thought that this would have been a problem that someone ran in to by now.

While it's not the most severe of issues, it comes to be a big hassle when you're attaching files of code and such.

Any help would be greatly appreciated.