I ran into an interesting issue today after a co-worker reported that he had been receiving emails from someone who claimed there were attachments, however they were not being displayed within the email.
After viewing the message source and seeing a base64 encoded block within the email, I wondered if it was Thunderbird doing something I didn’t expect. I checked it in Roundcube and other locations… worked fine elsewhere…
And then I downloaded: Show All Body Parts. Problem worked around for now. 🙂
Here are some more links for further information: