What MUA works with mail delivered by EXIM?
 

I receive mail on a server that uses EXIM as its MTA. The mail isn't put in 1 file in /var/spool/mail but in a file for each message in $HOME/mail/new What MUA will read this mail?

This looks like Maildir format. The linked Wikipedia article lists compatible mail readers at the end.

This is not the standard setting for Exim. If you're in charge for the server, you definitely can reconfigure Exim to use the traditional mbox format.

Thanks. It looks like Maildir, which is new to me. I could change the setting but it'd make others unhappy. The list of MUAs in that article includes mailx, what I already use, so I'll figure it out.

The man page says I need to set the MAILDIR environment variable. That didn't work; setting the MAIL environment variable did.

There are multiple implementations of mailx available in Linux distros: Heirloom mailx, S-Nail, GNU Mailutils, BSD mail. The latter doesn't understand the Maildir format at all.

The mailx package in Slackware 14.2 is Heirloom mailx whereas Slackware-current provides S-Nail.

I was reading the man page of the version I was running. In any case knowing this may help the occasional other dinosaur with the same problem.