Don't bother starting to automate with Perl (Email::Sender is super sweet) until you can get a successful SMTP session manually. This decade's best practice: encryption, authentication, submission port. Try variations of this:

$ echo '\000mysmtpusername\000mysmtppassword' | openssl base64
XDAwMG15c210cHVzZXJuYW1lXDAwMG15c210cHBhc3N3b3JkCg==

$ # ↑↑↑↑ copy this to clipboard

$ openssl s_client -connect mailhost.faraway.example.net:587 -starttls smtp

ehlo hostname.here.example.org
auth login XDAwMG15c210cHVzZXJuYW1lXDAwMG15c210cHBhc3N3b3JkCg==

and you know the rest:

mail from: <samwyse@host.here.example.org>
rcpt to: <fnord@example.com>
data
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