[9front] Incoming mails disappearing

[sirjofri <sirjofri+ml-9front@sirjofri.de>]

Hello all,

For some time already I noticed that my incoming mails are sometimes 
disappearing from my inbox. They have enough time to show up on my phone 
(FairEmail client). First I thought it's only the mails I send to myself 
via cron (for people asking: calendar output and a todo file), but it 
just recently affected a mail I got from ori (who kindly sent the mail 
again so I can read it).

Here are some conditions for mails that are affected and also some 
details:

Only mails in my personal inbox (mbox directory) are affected. Mails that 
are filtered and go to a different directory (ahemm, mailing lists) were 
never removed from their directory.

I can see the mails arriving on my phone for a short amount of time (~1 
second) and it feels like I can open them when I click the notification 
fast enough. Sometimes however, I am just directed to my inbox directory 
and the mail is missing.

The mails are really removed, not just hidden from imap. I wasn't able to 
find the mails in the box directories, the queue or any tmp directory 
that's used while processing.

I might have a weird configuration somehow. Did someone else notice any 
similar issues? Any idea what might be wrong?

Using upas for years now and the issue wasn't bad for me personally until 
a day ago when ori sent me that mail...

sirjofri