problem with postfix rejecting email

[Ian Ward Comfort]

On Dec 4, 2007, at 8:00 AM, Bill Tangren wrote:
> I'm having a problem with postfix, version 2.2.10-1.1.el4. Because  
> of the screwy firewall configuration here, some lcoal email comes  
> in to my email server with no reverse DNS entry. I had been  
> rejecting those, but now that some of our own email is coming in  
> that way, I need to turn it off. I thought I had been using  
> reject_unknown_sender_domain to reject such email, but when I  
> comment it out, I'm still rejecting email with no reverse DNS entry.

reject_unknown_sender_domain rejects messages when the domain part of  
the SMTP sender address cannot be found in DNS.

> My question: How do I turn this feature off?
>
> This is an example of a rejection in the log:
>
> Dec  4 10:49:47 aa postfix/smtpd[19280]: NOQUEUE: reject: RCPT from  
> unknown[x.x.x.x]: 450 Client host rejected: cannot find your  
> hostname, [x.x.x.x]; from=<emailaddy> to=<localuser> proto=ESMTP  
> helo=<sender>

Look for a reject_unknown_client directive in one of the  
smtpd_mumble_restrictions in your main.cf -- then remove it.

--
Ian Ward Comfort <icomfort at rescomp.stanford.edu>
System Administrator, Student Computing, Stanford University