Tearing my hair out here! With High Sierra, PDFs would not download if a Rule moved the email with the PDF to a different folder in Mail. Now with Mojave, no PDFs are downloading, even in the main folder (PDF says "Downloading..." but doesn't). Sometimes quitting Mail helps, but rarely. This has been a problem for far too long :(
MacBook Pro 15", macOS 10.14
A couple things you can try…
Test from a different user account.
Test while in Safe Mode.
Use safe mode to isolate issues with your Mac - Apple Support
You might want to try Safe Mode first. That way you won't have to set up Mail for the new user account.
Having cancelled the Mail rule that moves messages to various folders, it would appear that I am no longer experiencing the "never-ending downloading" problem - at least with one particular sender. However, it's early days. I'll keep in touch.
Next chapter! Prior to trying Safe Mode I noticed that the particular .png files send to me via email (which showed the never-ending "Downloading..." message) to my Apple Mail occasionally do show the content, but it's random! Anyway, I tried Safe Mode, which didn't change anything: the already-sent png files remained forever downloading. I have now cancelled the Mail rule that has incoming emails saved to a different folder to see if it's the rule that's causing the problem. I'll report back.
I spoke too soon: cancelling the Rule that moves certain emails to a folder has not solved the issue. Some attachments are still featuring the never-ending download problem. It's as if High Sierra and now Mojave think these attachments are suspect - which they're not. Safe Mode was inconclusive. There are many other users suffering from this problem, but not everyone - so what can it be due to? And what's the next thing to try?
Not sure what you mean. I have no problem saving a PDF attachment using Mail.
I'm not the only one suffering from the dreaded never-ending "Downloading..." issue. Seems that Apple haven't got around to fixing it. All I can say is lucky you!
I have 5 Macs currently. They all work. I'm not THAT lucky.
Well as a Level 8 contributor, perhaps you could suggest things that might help me and others in my situation?
OK, will do when I have a break.
One more thing: sometimes (but not always) attachments will download if I quit and restart Mail.
Apple Mail: PDFs never actually download
