I have a machine that handles multiple virtual domains. Some of these include aliases defined for those specific domains (domain names will be changed from real names).
I have, for example:
$ cat /etc/exim4/virtual/alias.domain.com
hibak: "|/usr/local/bin/mail2redmine.sh blah"
And, of course alias.domain.com
is included in dc_other_hostnames
in /etc/exim4/update-exim4.conf.conf
.
It worked fine on debian jessie, but after upgrading to stretch, the virtual hostnames ceased to work. Getting a letter for them created such an entry in the rejectlog:
2018-02-19 17:03:21 H=from.host [REDACTED] F=<REDACTED> rejected RCPT <hibak@alias.domain.com>: Unrouteable address
exim -bt hibak@alias.domain.com
returns
R: system_aliases for hibak@alias.domain.com
hibak@alias.domain.com is undeliverable: Unrouteable address