Install libsendmail-milter-perl by entering the following commands in the terminal:
sudo apt update sudo apt install libsendmail-milter-perl
Description:
Interface to Sendmail's Mail Filter API
Sendmail::Milter is a Perl extension to sendmail's Mail Filter API (Milter). . With this module, Perl callbacks can be defined and registered with the Milter engine. This module calls those perl callbacks using interpreters from a threaded persistent interpreter pool.
Homepage: http://search.cpan.org/dist/Sendmail-Milter/
Version: 0.18-8build3
Section: universe/perl