Email to the archives fails with:
Jan  8 17:07:02 moog sendmail[24494]: r09172nC024493: to="|/home/mailman_7/mail/_truncating_wrapper_7a post eab_archive", ctladdr= (8/0), delay=00:00:00, xdelay=00:00:00, mailer=prog, pri=316823, dsn=5.3.0, stat=unknown mailer error 2

See Adding a Mailman installation when adding a new website. about how to deal with /etc/smrsh

_truncating_wrapper_7a is a script that must be setuid apache:

-rwxr-sr-x 1 root apache  3760 Jan  8 20:24 truncating_wrapper_7
-rwxr-sr-x 1 root apache  4010 Jan  8 20:25 _truncating_wrapper_7a
-rwxr-sr-x 1 root apache 20013 Oct 25 14:25 wrapper_7

For setuid scripts to work, sperl must be installed.