Perl Net::SMTP - How to use - perl

Question

Okay, I just spent the last four hours trying to figure out why my implementation of Net::SMTP module was no longer working.
In short, I was doing this (removing error checking stuff for clarity):
my $smtp = Net::SMTP->new(Host => $host);
$smtp->send($from);
$smtp->data;
$smtp->datasend($message);
$smtp->dataend;
$smtp->quit;
This had worked before, but now I was getting:
Net::SMTP=GLOB(0x7f9893114798)>>> SEND FROM:<from#address.com>
Net::SMTP=GLOB(0x7f9893114798)<<< 450 Unable to send to "<from#address.com" at this time
This was from my send method.
The Perldoc wasn't too much of a help because the send, send_and_mail, send_or_mail, and mail commands are all described together, and I had assumed were pretty much aliases of each other.
I looked at other examples and decided to try $smtp->mail and not $smtp->send That worked.
So, what are the differences between the send, mail, send_and_mail, and send_or_mail methods?. Do I need to try each one? I know they correspond to the MAIL, SEND, SOML and SAML commands in SMTP, but I can't really find anything that tells me what the differences are. And, do different SMTP servers use different commands. (Maybe that's why the send method previously worked?)

Answer 1

The Net::SMTP docs mention that you're supposed to be familiar with the SMTP protocol. That's currently specified by RFC5321. Appendix F.6 of RFC5321 discusses the now-obsolete SEND command. (It was supposed to deliver a message directly to the terminal, but that was rarely implemented. Some servers may have interpreted it as a synonym for MAIL.)
The short version is that you should be using the MAIL command. Or, even better, a higher-level module like Email::Sender.

Answer 2

From RFC 5321, appendix F.6:
"In addition to specifying a mechanism for delivering messages to
user's mailboxes, RFC 821 provided additional, optional, commands to
deliver messages directly to the user's terminal screen. These
commands (SEND, SAML, SOML) were rarely implemented, and changes in
workstation technology and the introduction of other protocols may
have rendered them obsolete even where they are implemented.
"Clients SHOULD NOT provide SEND, SAML, or SOML as services. Servers
MAY implement them. If they are implemented by servers, the
implementation model specified in RFC 821 MUST be used and the
command names MUST be published in the response to the EHLO command."