After applying the workaround quoted as follows, it works for me:
Quote[
yeah ... the cause is that location of global config files moved down
one folder. Previously we had a hack that allowed you to drop configs
in /etc/icedove/ ... now we have a clean solution that introduces an
official syspref foloder, which is:
$ ls -l /usr/lib/icedove/defaults/syspref
lrwxrwxrwx 1 root root 17 Jun 1 22:35
/usr/lib/icedove/defaults/syspref -> /etc/icedove/pref
... so copying your current /etc/icedove/ files to /etc/icedove/pref/
should fix this for you ... if not, then I forgot to apply the syspref
patch ... so let me know if this workaround actually works for you.
]