Install libnet-smtp-tls-butmaintained-perl by entering the following commands in the terminal:
sudo apt update sudo apt install libnet-smtp-tls-butmaintained-perl
Perl module for providing SMTP client supporting TLS and AUTH
Net::SMTP::TLS::ButMaintained is a TLS and AUTH capable SMTP client which offers an interface that users will find familiar from Net::SMTP. Net::SMTP::TLS::ButMaintained implements a subset of the methods provided by that module, but certainly not (yet) a complete mirror image of that API.