I have written following code.

use MIME::Lite; 
# set up email
$to = "myname\@domain.com";
$from = "myname\@domain.com";
$subject = "Email Sent via Perl";
$message = "This email was sent using Perl.";

# send email
email($to, $from, $subject, $message,);

# email function
sub email
{
 # get incoming parameters
 local ($to, $from, $subject, $message) = @_;

 # create a new message
 $msg = MIME::Lite->new(
  From => $from,
  To => $to,
  Subject => $subject,
  Data => $message
 );

 # send the email
 MIME::Lite->send('smtp', 'microsoft.exchange.server', AuthUser=>'myna
+me', AuthPass=>'my_password', Debug=>1);
 $msg->send();
}
[download]

When I am executing the code. I am getting following error.

MIME::Lite::SMTP>>> MIME::Lite::SMTP
MIME::Lite::SMTP>>>   Net::SMTP(2.29)
MIME::Lite::SMTP>>>     Net::Cmd(2.26)
MIME::Lite::SMTP>>>       Exporter(5.58)
MIME::Lite::SMTP>>>     IO::Socket::INET(1.29)
MIME::Lite::SMTP>>>       IO::Socket(1.29)
MIME::Lite::SMTP>>>         IO::Handle(1.25)
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 220 CAS1.microsoft.exchange.server
+ Microsoft ESMTP MAIL Service ready at Mon, 4 May 2009 13:39:01 +0530
MIME::Lite::SMTP=GLOB(0x1b5e3e4)>>> EHLO localhost.localdomain
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-CAS1.microsoft.exchange.server
+ Hello [172.16.4.115]
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-SIZE 10485760
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-PIPELINING
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-DSN
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-ENHANCEDSTATUSCODES
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-STARTTLS
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-AUTH GSSAPI NTLM
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-8BITMIME
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250-BINARYMIME
MIME::Lite::SMTP=GLOB(0x1b5e3e4)<<< 250 CHUNKING
No SASL mechanism found
 at C:/Perl/site/lib/Authen/SASL.pm line 74
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The server through which I am trying to send the email is an Microsoft exchange Server.

Just FYI - I generally use 'Thunderbird' as my email client I am being able to send/receive emails through exchange server.

Under SMTP section following settings are configured:

Port: 25
Use secure connection: No

On the other hand to receive emails I am using port 993 through SSL