Well, I thought the problem had resolved itself, as a later message from my colleague opened both the PDF attachment and the graphic below her signature! Sadly a subsequent message she sent had the same issue -- empty attachment, no offer to open it in Adobe/PDF, and an empty graphic below her signature.

I am checking suggestions in Thunderbird Help and see other users have similar issues but not a lot of answers at this point If anyone can suggest what might have happened, that would be interesting -- especially opinions if we are looking at a bug here, or if I may have a unique problem.

sounds like an anti virus that was loosing the plot that a reboot may have reset on the straight and narrow.

Hello Matt, thanks for the reply! I'm not sure I understood it completely. Can you say it in a different way?

I have had issues like this particularly after a message has been moved to another folder automatically by a filter.

I know that I can open the message to view its source and see the allegedly missing content - usually for an image or video. I can even select and copy the data, convert it from base-64, save it as a file with an appropriate extension and then open it in the normal way.

Another "fix" is simply to save the broken message as an eml file, say on your desktop, and then open that eml file by double-clicking it. It will open in your default email client, or whatever has been nominated to handle eml files (usually Thunderbird) and generally with all the content intact.

Contrary to Matt's suggestion about anti virus being the root cause, this happens to me in an environment where there is no firewall or anti-virus. In my case, it's the moving of the email message to another folder where the problem seems to arise.

Zenos, thank you for your comment: "I have had issues like this particularly after a message has been moved to another folder automatically by a filter. "

I believe that is exactly my issue. I moved the problematic messages back to the Inbox and opened them there. The attachments and images came back.

• When a message filter moves a message from the Inbox to one of my folders, does it leave the image and attachment behind?
• Does this operation change one or more of its attributes to where they are no longer recognized?
• Does the location of a message make a difference?
• Is the "fix" to undo all my message filtering?

Updating my reply:

Try moving the message from the folder back to your Inbox and see if the graphics and attachments are available there. So far I have found this to be a pretty consistent workaround. I went to Bugzilla and opened a Bug # 1401396 on this.

Another user suggested changing the filter so that it operated after classification and not before (which seems to be the default). Supposedly this would buy more time for the complete message with all its contents to be moved.

change your filter to act "after classification". if it is as discussed by Zenos the added delay should fix it for you. My assumption is that the email gets moved before it completely gets downloaded. normally when their are attachments. Given junk classification uses the message body, it delays the filter execution.

I do wonder if it might be worth filing a bug. I am seeing these sorts of questions more often and with faster computers with faster connections it might be one of those problems that are "emerging" and needs to be monitored if not outright fixed.