sa-exim binary package in Ubuntu Focal amd64

 SA-Exim integrates SpamAssassin filtering at SMTP time with the Exim
 v4 MTA. It may be used to reject incoming mails before they arrive, or
 even to tie up the sender's resources by slowing down the connection
 ("teergrubing").
 .
 Most of the functionality of this package can also be achieved
 using the exiscan ACL conditions built into the "heavy" Exim daemon,
 exim-daemon-heavy. Use this package if you need SpamAssassin's
 report_safe feature, or if you want to have easier control over the
 header fields added, without using the report template to add multiple
 fields.

Source package