Mfcheck + Qmail on a cable modem.
 

I have 2 email servers. One is running on a t1 and the other is running on a cable modem. The one on a t1 has the mfcheck patch running. We can email people on the cable modem server without any problem. However when the cable modem server emails the t1 server I get no emails and nothing in my logs to show it recieved it. The cable modem server's logs show it sent fine without a problem. I believe this might be caused because the cable modem has a valid domain but the ip is reversed to one of our isp's hostnames. Has anyone ever had this problem with qmail or the mfcheck patch? Or can anyone give me a clue because I have racked my brain completely. Thanks

Justyn

mfcheck is supposed to do a reverse lookup on the domain part of the envelope sender. This ensures that you're able to bounce the message properly. So what domain are you using when you send messages to the mail server on your T1? Are you sure the messages aren't in the queue? Maybe you're looking at the wrong log. Be sure to look at the qmail-send logs on the sending mail server.

Postive I'm looking at the right logs on the t1 server. Im using dtetechnologies.com which is pointed to our cable modem ip. No email stuck in the queue.


Justyn

Ok, let me be sure I understand... you mean everything on both systems was working fine before but now things are not working right? Or this is a new installation on both machines and you're trying to get them both working??? If these are new setups, then maybe there are basic delivery problems.

On your sending machine, there should be entries written to the qmail-send log or /var/log/maillog (depending on how you've got things setup) that shows qmail connecting to the remote IP address and delivering the message. You're saying there is NOTHING being written to the logs when you send mail?? Is it possible something is down? Maybe logging is not taking place? Run qmailctl stat and see if logging is running. Is it logging deliveries to other hosts but simply not logging for mail being sent to your T1?

No. My cable server is using a older package of qmailrocks. I installed it before they had a slackware walkthrough. And I have manually updated all the packages by hand (qmail,qmailadmin,qmail-scanner,etc). The t1 server is a new box. Brand spanking new.

On the sending machine (my cable server) I see the t1 server has accepted the email in qmail-send logs. However on the reciever machine (t1 server) I dont get email nor do I see anything remotely related to the email in the logs. Nothing saying it was rejected either.

The odd thing is if I send from the cable server to the t1 server to an address that does not exist (thisaddressdontwork@myt1domain.com) I get a reply back from the t1 server that this person does not exist.

I'm ASSUMING this...
Since my domain hosted on my cable server is set to a cable ISP's ip. The t1 server is rejecting the email because when it does a dns reverse on the email the ip does not reverse back to my domain. It reverses back to my-ip.home.isp.com. I know I installed 2 anti-spam patches that are suppose to block email that dont reverse right (ie: mfcheck.patch)

Does this make sense? I've never ran into this problem. Any ideas?


Thanks

Justyn

>> The t1 server is a new box. Brand spanking new.

Maybe something is misconfigured in there.

>> I see the t1 server has accepted the email in qmail-send logs

That's good. But doesn't tell us much because we know the configuration works because this machine has been running for a while without problems.

>> Nothing saying it was rejected either.

I recommend testing it via telnet, as that is easier and shows you the server's responses.

For example...

[root@slaveone root]# telnet falcon 25
Trying 192.168.0.60...
Connected to falcon.
Escape character is '^]'.
220 falcon.mydomain.com ESMTP
helo spammer
250 falcon.mydomain.com
mail from: aksdfh@lkdfhsldhf.hhj
553 sorry, your envelope sender domain must exist (#5.7.1)

This shows the mfcheck patch doing it job by trying to reverse lookup on the domain I put for the "mail from" line.

>> I get a reply back from the t1 server that this person does not exist.

Hmm... this certainly suggests that everything is configured right on the new box. But it's not normal for qmail to discard messages into the ether.


>> The t1 server is rejecting the email because when it does a dns reverse on the email the ip does not reverse back to my domain.


Your server will only do what you tell it to do. It will not do this by default.


>> I know I installed 2 anti-spam patches that are suppose to block email that dont reverse right (ie: mfcheck.patch)


What might the other one be?? This may be the issue. Maybe your patch didn't get applied properly. Maybe it's not logging properly. Maybe the patch you applied was bad.