I have successfully used code like below for sending via my local net-provider:

$response = Email::Sender::Simple::sendmail(
   $emailobj,
   {'transport' => Email::Sender::Transport::SMTPS->new($smtp_params)}
);
[download]

where $emailobj is produced using Email::MIME->create() and then keep adding attachments to it.

There are a few examples at the manpage of Email::MIME. If you need more concrete help let us know. I am not posting anything else as I don't know if this is a 2020-approved method.

bw, bliako