User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.9) Gecko/20100101 Goanna/4.1 Firefox/60.9 PaleMoon/28.2.2 Steps to reproduce: I set a filter for all incoming mail on my Gmail account: Apply filter when: - Manually run - Getting new mail - before junk classification Match all messages; Perform these actions: - Copy Message To Inbox on Local folders - Delete Message I also remember that using Move Message has the same problem. Actual results: If only one mail is received at a time, the filter works correctly. Second, third and possibly more messages are displayed empty in the Inbox if they are received simultaneously. Example of the source of an empty message: From - Sun Dec 09 13:02:52 2018 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 X-Mozilla-Keys: Expected results: All messages should be copied correctly. I can workaround the issue by copying the messages manually again.

Did this fail also in version 52? If not, how long have you seen this in version 60? Do you have any add-ons installed

Sorry, I never used version 52. I only started to use Thunderbird recently. No addons, spam filter disabled, version 60.2.1 in Ubuntu 18.04 - maybe it's the problem.

Gene, you have lots of test accounts - have one where you don't care if you lose data to test this? :)

On 52 now and did the test. I don't see anything copied to Local Folders by the filter. Also with or without the delete step after the copy in the filter, I only see the newly arrived gmail Inbox message (or messages) in the All Mail folder and not in Local Folders! Tried filtering on a subject string and made no difference (nothing copied to Local Fs). Changed to apply filter *after* junk classification seems to work OK with 1 or multiple messages using the reporter's filter setup otherwise (newly arrived messages are copied to Local Folders and deleted from gmail Inbox and All Mail and also don't appear in gmail Trash). Haven't tried this on 60.* yet. Was something changed on after 52.9.1 that affects filtering?

I tried to use "After junk classification", it seems to fix the destruction (still not completely sure though), but now the filter sometimes activates twice, resulting in two copies of the same email in Local Inbox.