SMTP 450 when sending mail with Net::SMTP - perl

Question

SO.
I'm failing at sending mail from my Perl script. This is what my code looks like:
use Net::SMTP;
$smtp = Net::SMTP->new("smtpserver.mydomain.com");
$smtp->mail("myemail\#mydomain.com");
$smtp->to("myemail\#mydomain.com");
$smtp->data();
$smtp->datasend("From: myemail\#mydomain.com\n");
$smtp->datasend("To: myemail\#mydomain.com\n");
$smtp->datasend("Subject: Test message\n");
$smtp->datasend("Just a test message.\n");
$smtp->dataend();
$smtp->quit;
This is what the debug option throws:
Net::SMTP>>> Net::SMTP(2.31)
Net::SMTP>>> Net::Cmd(2.29)
Net::SMTP>>> Exporter(5.64_03)
Net::SMTP>>> IO::Socket::INET(1.31)
Net::SMTP>>> IO::Socket(1.32)
Net::SMTP>>> IO::Handle(1.31)
Net::SMTP=GLOB(0x1d1a06c)<<< 220 ESMTP Postfix
Net::SMTP=GLOB(0x1d1a06c)>>> EHLO localhost.localdomain
Net::SMTP=GLOB(0x1d1a06c)<<< 250-
Net::SMTP=GLOB(0x1d1a06c)<<< 250-PIPELINING
Net::SMTP=GLOB(0x1d1a06c)<<< 250-SIZE
Net::SMTP=GLOB(0x1d1a06c)<<< 250-ETRN
Net::SMTP=GLOB(0x1d1a06c)<<< 250-STARTTLS
Net::SMTP=GLOB(0x1d1a06c)<<< 250-ENHANCEDSTATUSCODES
Net::SMTP=GLOB(0x1d1a06c)<<< 250-8BITMIME
Net::SMTP=GLOB(0x1d1a06c)<<< 250 DSN
Net::SMTP=GLOB(0x1d1a06c)>>> MAIL FROM:<myemail#mydomain.com>
Net::SMTP=GLOB(0x1d1a06c)<<< 250 2.1.0 Ok
Net::SMTP=GLOB(0x1d1a06c)>>> RCPT TO:<myemail#mydomain.com>
Net::SMTP=GLOB(0x1d1a06c)<<< 450 4.7.1 <localhost.localdomain>: Helo command rejected: Service temporarily unavailable
Net::SMTP=GLOB(0x1d1a06c)>>> DATA
Net::SMTP=GLOB(0x1d1a06c)<<< 554 5.5.1 Error: no valid recipients
Net::SMTP=GLOB(0x1d1a06c)>>> From: myemail#mydomain.com
Net::SMTP=GLOB(0x1d1a06c)>>> To: myemail#mydomain.com
Net::SMTP=GLOB(0x1d1a06c)>>> Subject: Test message
Net::SMTP=GLOB(0x1d1a06c)>>> Just a test message.
Net::SMTP=GLOB(0x1d1a06c)>>> .
Net::SMTP=GLOB(0x1d1a06c)<<< 221 2.7.0 Error: I can break rules, too. Goodbye.
Net::SMTP=GLOB(0x1d1a06c)>>> QUIT
The interesting part is that the SMTP server replies with 250 OK when I talk directly to it and I receive the mail just fine:
220 ESMTP Postfix
MAIL FROM:<myemail#mydomain.com>
250 2.1.0 Ok
RCPT TO:<myemail#mydomain.com>
250 2.1.5 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
Just a test message.
.
250 2.0.0 Ok: queued as B68672C02B
Does someone have some light to shed?
Thanks in advance.

Answer 1

Just posting this as an answer instead so that it can be accepted as the answer, as requested by triplee.
Something might be wrong in your domain setup.
also add $smtp->datasend("\n"); underneath $smtp->datasend("Subject: Test message\n"); in a new line, else it will not show mesage text.
like this.
$smtp->datasend("Subject: Test message\n");
$smtp->datasend("\n");
$smtp->datasend("Just a test message.\n");

Answer 2

The SMTP server (postfix) "does not like" hostname used in EHLO command but rejects it in reply to RCPT TO: command.
>>> MAIL FROM:<myemail#mydomain.com>
<<< 250 2.1.0 Ok
....
>>> RCPT TO:<myemail#mydomain.com>
<<< 450 4.7.1 <localhost.localdomain>: Helo command rejected: Service temporarily unavailable
You can make Net::SMTP use another hostname in HELO/EHLO command by passing Hello parameter to new.
$smtp = Net::SMTP->new('smtpserver.mydomain.com', Hello => 'host.example.net');