So I have been in the process of installing a Postfix Server on my CentOS 6.2 Virtual Private Server.

I have been following this tutorial:


Because I have never set up a Mail Server before.

So everything has worked fine up until the 5th page.

I am on step 15. It shows how to verify that Postfix is ready for SMTP-AUTH and TLS, but when I run the commands:

telnet localhost 25

and get:

Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 server1.example.com ESMTP Postfix

So I type:

ehlo localhost

I get:

250-server.cdevelop.info Hello localhost [], pleased to meet you
250 HELP

So there is no:


Which by the guide, and common sense, shows that it isn't ready for SMTP-AUTH nor TLS. Everything has been installed in the Guide, and configured the way stated, but I am still getting this problem.

What should I be looking into? either configurations, or verify packages are installed or Error logs, etc.?

Is there anymore information I should provide to you folks?

Or just anything else anyone would like to say about this that may help my situation.

And if you can't provide any help or information, would someone mind pointing me to some good tutorials on setting up a lightweight mail server on my CentOS VPS? I really like the tutorial I am following now, because it allows Virtual Domains and Virtual Users, making it lighter, and more customizable. So if I could integrate virtual users and domains into another tutorial that would work too.


1 Answer 1


Just to be certain, double check you main.cf (/etc/postfix/main.cf on my Ubuntu distros not 100% sure for CentOS) and make sure that you have:

smtpd_sasl_auth_enabled = yes
broken_sasl_auth_clients = yes

I am by far not an expert in MTAs, but I have at least gotten far enough into to get mine to give me the AUTH and AUTH= responses and those two lines are what give you those results.

Just in case you are curious, from what I have been able to glean from reading guides and such, the smtpd_sasl_auth_enabled = yes line enables the AUTH {mechanisms} line of the response telling compatible clients that the authentication mechanisms are available. Make sure that you didn't leave off a letter somewhere like the 'd' in 'smtpd'. The broken_sasl_auth_clients = yes is to give the AUTH={mechanisms} response which I only skimmed that part and saw something about 'unsupported', 'clients' and 'outlook', then rolled my eyes and muttered a few choice words involving Microsoft.

Now for the STARTTLS stuff, I may not be 100% useful on that because I haven't yet tested TLS, since I am still working on transmitting mail on my server. I receive mail fine and courier authenticates IMAP users, but my Cyrus-SASL auth is failing the SMTP. I will do my best here and tell you I know the settings I have for it are:

smtpd_tls_cert_file = /etc/postfix/smtpd.cert
smtpd_tls_key_file = /etc/postfix/smtpd.key
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

smtp_tls_security_level = may

I am afraid that all I can tell you about that is, again, make sure that you didn't miss a letter or an '_' where needed and check and make sure you haven't commented out a setting. As someone who is stumbling through postfix/mysql/cyrus-sasl/courier-imap(-ssl)/pam configuration and has stumbled through other configurations before, I can tell you I've done that more times than I care to admit to.

  • Okay, FINALLY got mine authenticating via cyrus-SASL, so now I'm 100% up and running and I hope that I can help you do the same. Jun 22, 2013 at 18:06
  • Just be careful not to leak your SMTP password in a downgraded StartTLS session and also be sure not to leak your TLS private certificate keys by allowing the use of SSL (v2 or v3).
    – JohnW
    Oct 2, 2016 at 16:20

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .