Mail Admin wrote:
Thunderbird continues to behave erratically with dovecot test builds. I haven't been able to test the imap_client_workarounds=tb-negative-fetch option yet as I'm still running test52. Thunderbird displays blank messages when they are opened, but "Edit as new" shows the message contents.
I'm also seeing this very occasionally.
I'm pretty sure its a TB bug as looking at the same maildir via Mutt/dovecot shows the proper contents. My guess is it's the same underlying bug that the tb-negative-fetch workaround helps, and that for some reason TB is caching bogus information about that UIDL. I haven't yet worked out how to flush TB's header cache and re-fetch all the headers (short of removing dovecot's index files....)
Refiling the busted message to a new folder then back again fixes it.