[Users] Never ending cert update requests for one mailbox ?

[Michael]

Hello,

This is claws 3.17.3 on Debian testing. 

Since a few days, claws nags me really often about certificate updates for my provider (posteo) ... the old cert expires 22.01.2019 so that seems correct. But i've seen at least 10 such requests right now. I don't understand why so often.

I looked into the cert folder and it shows this:

-rw-r-----  1 mic mic 1854 Jan 19 16:37 posteo.de.110.cert
-rw-r-----  1 mic mic 4232 Jan 19 23:56 posteo.de.110.cert.chain
-rw-r-----  1 mic mic 1854 Jan 19 23:54 posteo.de.25.cert
-rw-r-----  1 mic mic 4232 Jan 19 23:54 posteo.de.25.cert.chain
-rw-r-----  1 mic mic 2013 Oct 24  2014 posteo.de.465.cert
-rw-r-----  1 mic mic 4963 Oct 26  2014 posteo.de.465.cert.chain
-rw-r-----  1 mic mic 2013 Apr 24  2014 posteo.de.587.cert
-rw-r-----  1 mic mic 4963 Oct 23  2014 posteo.de.587.cert.chain
-rw-r-----  1 mic mic 2013 Apr 23  2014 posteo.de.995.cert
-rw-r-----  1 mic mic 4914 Oct 26  2014 posteo.de.995.cert.chain

Is that a 'normal' history ? 

For Posteo, i've 2 claws POP accounts for 2 mail addresses (aliases) of the same Posteo mailbox, with else identical settings. 
I poll only one account though, because that gets me the whole inbox anyway. But i use the second account for sending.

Configuration: 

POP with STARTTLS. In the 'Advanced' section, i've port 587 for SMTP and 110 for POP. (I wonder why 587 isn't shown in the cert list though.)

I have other accounts / mailboxes in claws, like this GMX one and i never seen that much cert request for these. If any.