SMTP : Email are not getting delivered

Question

I have a SMTP Authentication Support 7.x-1.0 module in D7. Its enabled and configured correctly with permissions.

Emails are not getting delived, I dont know what is the issue here. Am I missing something here?

Tried/checked following things:

1. SMTP server is running, tested it. From command line emails are getting delivered.
2. No change in any of the core Drupal 7 modules and in SMTP module.

3. No errors found in drupal reports/ smtp logs

   This is what I am getting when I try to check SMTP test email.

- SMTP.module is active.     
 - The configuration options have been saved.
 - SMTP.module is active.
 - A test e-mail has been sent to    [email protected].
 - You may want to check the logs for    any error messages.

Following is the debugging output.

SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "220 mycompanydomain.com ESMTP Postfix " 
SMTP -> get_lines(): $data is "220 mycompanydomain.com ESMTP Postfix " 
SMTP -> FROM SERVER:220 mycompanydomain.com ESMTP Postfix 
SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "250-mycompanydomain.com " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com " 
SMTP -> get_lines(): $data was "250-mycompanydomain.com " 
SMTP -> get_lines(): $str is "250-PIPELINING " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com 250-PIPELINING " 
SMTP -> get_lines(): $data was "250-mycompanydomain.com 250-PIPELINING " 
SMTP -> get_lines(): $str is "250-SIZE " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com 250-PIPELINING 250-SIZE " 
SMTP -> get_lines(): $data was "250-mycompanydomain.com 250-PIPELINING 250-SIZE " 
SMTP -> get_lines(): $str is "250-ETRN " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN " 
SMTP -> get_lines(): $data was "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN " 
SMTP -> get_lines(): $str is "250-ENHANCEDSTATUSCODES " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN 250-ENHANCEDSTATUSCODES " 
SMTP -> get_lines(): $data was "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN 250-ENHANCEDSTATUSCODES " 
SMTP -> get_lines(): $str is "250-8BITMIME " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME " 
SMTP -> get_lines(): $data was "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME " 
SMTP -> get_lines(): $str is "250 DSN " 
SMTP -> get_lines(): $data is "250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN " 
SMTP -> FROM SERVER: 250-mycompanydomain.com 250-PIPELINING 250-SIZE 250-ETRN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN 
SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "250 2.1.0 Ok " 
SMTP -> get_lines(): $data is "250 2.1.0 Ok " 
SMTP -> FROM SERVER:250 2.1.0 Ok 
SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "250 2.1.5 Ok " 
SMTP -> get_lines(): $data is "250 2.1.5 Ok " 
SMTP -> FROM SERVER:250 2.1.5 Ok 
SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "354 End data with . " 
SMTP -> get_lines(): $data is "354 End data with . " 
SMTP -> FROM SERVER:354 End data with . 
SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "250 2.0.0 Ok: queued as 29B7262 " 
SMTP -> get_lines(): $data is "250 2.0.0 Ok: queued as 29B7262 " 
SMTP -> FROM SERVER:250 2.0.0 Ok: queued as 29B7262 
SMTP -> get_lines(): $data was "" 
SMTP -> get_lines(): $str is "221 2.0.0 Bye " 
SMTP -> get_lines(): $data is "221 2.0.0 Bye " 
SMTP -> FROM SERVER:221 2.0.0 Bye