Bugzilla cannot connect to an SMTP server

In a fresh Bugzilla installation (5.0.3), on a Scientific Linux 6 server I can't set the mail parameters due to this error: The new value for smtpserver is invalid: Cannot connect to mail.smpt.server Despite the fact that SMTP settings are correct. The SMTP server for the company is fully functional, on that server I downloaded thunderbird and was able to log in to my account smoothly without any problem which should mean the server has no problem with SMTP at all. I'm still searching with no clear hind what the cause could be. Any help is really appreciated! Update: In the old installation I can set these values and I can submit a bug but the email is not sent. This article says that bugzilla does not support SMTP with authentication (Not sure if true or not). Update: I installed the necessary modules here and again no luck. Update: On the old installation (4.something), we managed to setup an email account without authentication. This Bugzilla can now send email and it should work smoothly. Update: I found this useful article which applies a custom send mail script but the error message could not tell me where the error is.