Date: Wed, 19 Jun 2002 13:55:49 -0500 From: Steve Fettig <lists@stevenfettig.com> To: Andrew <perl@ukrpost.net> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Mail Message-ID: <3D10D3B5.5020204@stevenfettig.com> References: <6138366788.20020619145251@ukrpost.net>
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Andrew wrote: > Hello list. > > I cannot send message to one host. My smtp server is running qmail. > I see in logs "451 unresolvable relay host name check your setup". > Andrew, I've been following this thread and had some similar problems. I'm going to shoot in the dark on this and see if it helps. If your mail server is saying hello to others as mail.yourdomain.com, then make sure your DNS server has an A/CNAME entry for mail.yourdomain.com and not just an MX (in the case of the dns server I use, you only need the mx and it creates the a/cname). That means that when someone does a dig/nslookup on mail.yourdomain.com, it will resolve. The other side of the problem was mentioned in another post -- does the ip resolve to an fdqn? Just to see what the "world" sees, you can go to a place like www.domainwhitepages.com and run a lookup on 123.456.789.111 - i.e. your IP - and see if it resolves for the world. If it doesn't, you need to make sure that it will resolve to some fdqn by properly configuring your dns server. In my experience, it doesn't even have to match your mail.yourdomain.com. Because I haven't gotten around to getting the IP's I use delegated to my dns server, they resolve out to the default that my upstream provider has set them at. This means that I have a situation like the above - the name of the server and fdqn of the IP don't match. I have yet to find a mail server that won't accept mails from me.** hth, Steve **I think this makes sense anyway - both fdqn's for resolution are valid and would give one enough information to trace abuse mails if that is why the receiving server requires it. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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