I upgraded my webserver to Debian Lenny last night. It went almost without problems. This was because I followed the release notes. This helped a whole lot.

Still this morning there was a small problem that I didn’t notice yesterday. I didn’t receive any email. So I took a look in the exim4 mainlog at /var/log/exim4/mainlog. It contained the following message:

lowest numbered MX record points to local host: servername

All messages that should be delivered in a local mailbox were frozen. The solution was actually quite simple. First I needed to change one line in a config file. It contained something that looked like: DEBCONFxxxDEBCONF. This is a line that would normally be replaced by the update-exim4.conf script. But that doesn’t work anymore.

Now the files conf.d/main/005_local_hostnames contains a line like this:

MAIN_LOCAL_DOMAINS = localhost:servername:dsearch;/etc/exim4/virtual

All hostnames on this line should be delivered locally.