In light of the above the bug seems to be cause by interaction of the
packages postfix, resolvconf, and network-manager by using postfix on a
portable desktop machine as opposed to a server with static network
configuration.
Since I am using mutt as mail client, I need a local MTA. Postfix seemed
I might have found the reason for this behaviour:
1) Without network connectivity, the file /etc/resolv.conf does not
contain any useful information (just two comment lines).
2) After establishing network connectivity, the file /etc/resolv.conf
contains 127.0.1.1 and a correct search path as rece
