Disclaimer: The setup described below is perhaps not ideal or The Best(tm), but my question is not about how to improve it, only about why it works the way it does...

My courier installation handles two domains. One of them, let's call it doma.se, is setup to be the local domain, the other one, domb.se is a virtual domain. For domb.se, there are no real users, so I've chosen to use aliasdir/.courier files to handle all the addresses for it. The address for doma.se are all listed in aliases/.

In aliases/ there is also a virtual domain definition:

@domb.se: domb

There is an address, al...@domb.se, which is handled by aliasdir/.courier-domb-all. The file reads: fo...@doma.se

fo...@doma.se is listed in aliases/ as :include:/my/file.alias

/my/file.alias contains a few addresses in the virtual domain domb.se. (The only reason why this list is not put in .courier-domb-all is because I wanted to make the list managable for a non-root user. Anyway, that's not important right now...)

The addresses in the alias all have a corresponding .courier file. For example, ap...@domb.se is handled by .courier-domb-apa which in turn contains a mail address to a remote user.

Now for the real question. This setup, naive as it may be, did work, until I upgraded my (stable) debian system. After that, mailing al...@domb.se stopped working. If I look in the log files, I see that each and every address in the file.alias is rejected with "User unknown."

For example, "courierd: id=X,from=Y,addr=<ap...@domb.se>: 550 User unknown"

But if I send a mail directly to ap...@domb.se, it works just as expected.

It would not surprise me if I didn't really get the configuration files right during the upgrade, so it could be that something more or less vital changed, but I still find it a bit strange...

What am I missing here?

Thanks, Mikael