There are no other files named mailer.abs in the archive.
MAILER - A message program for DEC-10's
MAILER is a complete mail utilty for the DECsystem-10. The mailer
includes both system and user mail support. The mailer includes group
processing, user notification, mail security and administrative
controls. The mailer is easily installed and fully documented. It is
similar to the mailers found on TOPS-20. MAILER is mainly written in
BLISS-10 with a couple of routines in MACRO.