Email problem, suggestions where I should post?

Email problems

[KeithBoynton]

I am experiencing some problems sending email from my site.

Some mails I am sending are getting bounced back with the following error:

 ----- The following addresses had permanent fatal errors -----
<[e-mail]>
 (reason: 550 [PERMFAIL] comcast.net requires valid sender domain)
 ----- Transcript of session follows -----
... while talking to gateway-s.example.net.:
>>> RCPT To:<[e-mail]>
<<< 550 [PERMFAIL] example.net requires valid sender domain
550 5.1.1 <[e-mail]>... User unknown

Does anyone have any ideas, or suggestions which forum to post this in?

Thanks in advance......

[edited by: Woz at 1:14 pm (utc) on May 23, 2004]
[edit reason] no specifics please, see TOS#13 [/edit]

[kwngian]

I think this is some kind of spam filter set by some ISP and web host which I have encountered before.

They will do a reverse lookup on the connecting ip address that is sending the mail and if it does not resolve to your domain (eg when you are sending the mail through your ISP's mail server) it will reject it. This is probably to stop spammers from connecting to mail servers directly and sending out spams.

You can try to send it through your hosting company's mail server. It should be alright.

[KeithBoynton]

Hi kwngian,

Thanks for the reply. To be clear these are automatic mails that are sent by the website code, for example when one of my members requests their forgotten login details etc.

The mails are being sent by my hosting company's mail server.

I have contacted my hosting company suggesting it is exactly the problem you have suggested but they are adamant it is not a problem with their mail server although cannot suggest what else it could be.

[kwngian]

Hello Keith

Try changing <[e-mail]> to <[e-mail]> and see if it works.

[edited by: Woz at 1:15 pm (utc) on May 23, 2004]
[edit reason] examplified [/edit]

[KeithBoynton]

Thanks for the idea, if will try that and see if it works...

[KeithBoynton]

Hmmm, no it doesn't I still get the same problem.

[john_k]

Some SMTP servers will require that the Reverse DNS lookup for the sending server's IP resolve to the same domain as the sending server.

You can check the reverse DNS for the domain at dnsstuff.com

If the reverse DNS checks out, then you should contact one of the blocking server's administrator directly and ask them for specifics on why the mail is being blocked.

If the reverse DNS shows that the IP belongs to something else than the sending domain, then you should contact your hosting company to get it fixed.

[kwngian]

I thought you were missing some A records for your domain.

Maybe there is some problem with the DNS configuration or maybe your hosting company's ip addresses are in the blacklist as john suggest.

I can't check anymore because your domain info was edited and I cannot remember what it was.

And, also make sure that you have an A record for your root domain ie example.com and not just a CNAME.

Thats all I can think of offhand. Sorry, I am unable to help.

[edited by: kwngian at 5:40 pm (utc) on May 24, 2004]

[KeithBoynton]

Hi John and Kwngian,

Thanks for that, I just did reverse dns on the ipaddress of the sending mail server and it resolves just fine.

I am sending the mail from [e-mail] which is correct and a very valid email address. The smtp server is called blahblah-griffin.com and reverse dns is correct.

Here are the headers of the original mail as received:

Received: from blahblah.griffin.com (blahblah.griffin.com [X.X.X.X])
by mail.freeservers.com (Postfix) with ESMTP id 4780237E90
for <[e-mail]>; Sat, 22 May 2004 02:31:20 -0600 (MDT)
Received: from blahblah2.mail.griffin.net.uk (blahblah2.griffin.net.uk [X.X.X.X])
by blahblah.griffin.com (Postfix) with ESMTP id 27FE0259331
for <[e-mail]>; Sat, 22 May 2004 09:04:19 +0100 (BST)
Received: from COLLECTIBLES [X.X.X.X] by blahblah2.mail.griffin.net.uk with ESMTP
 (SMTPD32-8.02) id A6893CE01F6; Sat, 22 May 2004 08:51:37 +0100
Subject: =?ISO-8859-1?Q?A_Collectibles_Top_25_Email_Enquiry?=
Sender: "=?ISO-8859-1?Q?blahblah@collectiblestop25=2Ecom?=" <[e-mail]>
From: "=?ISO-8859-1?Q?blahblah@collectiblestop25=2Ecom?=" <[e-mail]>
Date: Sat, 22 May 2004 09:03:08 +0100
To: "=?ISO-8859-1?Q?blahblah@nancysdreamhouse=2Ecom?=" <[e-mail]>

Here is the corresponding bounce I received:

<[e-mail]>: host mail.afcon.net[65.194.202.15] said: 451 4.1.8
 <[e-mail]>... Domain of sender address
 [e-mail] does not resolve (in reply to MAIL
 FROM command)

I have changed the machine names and ipaddresses for TOS reasons, does this make any sense?

[john_k]

of sender address [e-mail] does not resolve (in reply to MAIL FROM command)

It appears they are looking for the domain in the FROM address to either match the server or the reverse DNS (not sure which). You probably need to contact the administrator of the rejecting server.

[KeithBoynton]

Thanks for your help John, I did suspect that. I guess it's something that only the receiver can fix or is there anything I can do?

[john_k]

I guess it's something that only the receiver can fix or is there anything I can do?

I guess it depends on why it is being blocked.

[KeithBoynton]

Yep I'm sure your quite right, thanks for all your help :)