Hi, Matthias.
Just in case you haven't subscribed to the list, I'm writing
back to let you know another person besides confirmed that she
is seeing this problem. Unless she used BCC she doesn't seem to
have copied you. That's the norm for this list. It's just easier
to subscribe in order to get all of the responses. You can
easily unsubscribe -- if you so desire -- at any time.
I checked the Debian bug tracker.
https://www.debian.org/Bugs
There are a couple of bug reports listed for this version of
Icedove that seem as though they may be about this problem we're
seeing. I think the attempt to find the cause and a solution are
in very early stages.
If you wish to help you could try reading the information at
https://wiki.debian.org/Icedove#Debugging
and using the information provided there to collect some data on
your system. I intend to try it tomorrow -- if I get a chance.
I've got a very busy life right now. The bug isn't causing data
loss on my systems, so it doesn't have a really high priority
for me.
But I wanted you to know that the maintainers do seem to be
aware of the problem and are looking into it. The more people
like us help them, the quicker the problem might be resolved.
Best regards,
JP