[CentOS] postfix help. im clueless

Steve Friedman steve at adsi-m4.com
Mon Jun 4 16:33:11 UTC 2007

This issue is best dealt with in the postfix mailing list; however, there 
are a few things required to have any hope of understanding what is going 

0) which version of postfix are you running (you didn't indicate the 
version of centos)
1) postconf -n
2) are you running any of the daemons in chroot (see master.cf)
3) grep 553E01079AD /var/log/maillog

Finally, I am not exactly sure what problem you are seeing (I didn't send 
any data, but I appeared to pass the check that you were seeing).  So, I 
don't think that this is a postfix problem, but rather a transient DNS 
issue (which is why postfix responded with a temporary error (451) which 
causes a retry).  Troubleshoot your DNS plant, and not your SMTP plant.

> telnet 25
Connected to mail.elpanama.com (
Escape character is '^]'.
220 *** Bienvenido al Sistema IMSS ***
HELO eastern.pmei.com
250 mail.elpanama.com
MAIL FROM: <steve at pmei.com>
250 Ok
RCPT TO: <email.elpanama at elpanama.com>
250 Ok
221 Bye
Connection closed by foreign host.

Steve Friedman

On Mon, 4 Jun 2007, Erick Perez wrote:

> Hi, I have been given the task to check on a postfix server that
> presents the following error:
> Let's say you use your hotmail account and then send a message to one
> of my users. The postfix program running on the server responds:
> Jun  4 10:21:25 mail postfix/smtp[29744]: 553E01079AD:
> to=<email.elpanama at elpanama.com>, relay=localhost[],
> delay=54253, status=deferred (host localhost[] said: 451
> Unable to complete command, DNS not available or timed out (in reply
> to MAIL FROM command))
> first, why is giving me a timeout?
> and second, why in the response the to= field has the domain name?
> what things can i see in the main.cf?

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