fastforward binary package in Ubuntu Bionic s390x

 It can create forwarding databases from a sendmail-style /etc/aliases or
 from user-oriented virtual-domain tables.
 .
 fastforward supports external mailing lists, stored in a binary format for
 fast access. It has a tool to convert sendmail-style include files into
 binary lists.
 .
 fastforward is more reliable than sendmail. sendmail can't deal with long
 aliases, or deeply nested aliases, or deeply nested include files;
 fastforward has no limits other than memory. sendmail can produce corrupted
 alias files if the system crashes; fastforward is crashproof.
 .
 fastforward's database-building tools are much faster than sendmail's
 newaliases. Even better, fastforward deliveries don't pause while the
 database is being rebuilt.
 .
 fastforward does not support insecure sendmail-style program deliveries from
 include files; you can use qmail's secure built-in mechanisms instead.
 fastforward does support program deliveries from /etc/aliases.

Source package