Issue Rejecting Email For Unknown Addresses

[davorg]

I'm running Plesk 12.5.30 on Centos 7.2. I'm using qmail to process email on the server.

One particular email address for one of the domains on the server started to get a lot of spam. It was an unnecessary address so I removed it. I want the server to reject email for this address (and, indeed, for all undefined addresses) but the server is still sending "this address no longer accepts email" addresses. As most of the spam comes from non-existent email addresses, this just generates "unable to deliver" emails to the postmaster.

In the Plesk control panel for the domain, I've selected "reject" in the non-existent users section of the mail configuration page. And I can see the domain listed in the /var/qmail/control/rejectnonexist file. And yet the spam emails are still accepted and the automated response emails are still being sent.

I must be missing something here. What am I doing wrong?

Thanks,

Dave...

 

[UFHH01]

Hi davorg,

with Plesk 12.5, you have the option to modify mail - settings to fight against spam. You might be intersted in the official Plesk documentation regarding your question:

Fighting Spam on a Qmail Mail Server ( Plesk 12.5 online documentation )​

...
To get rid of spam on your Qmail mail server:

1. Make sure that all domains have the option What to do with mail sent to non-existent users set to Reject.
   To change the value of this option for a domain, open it in the Control Panel, go to the Mail tab and click Change Settings.

=> Home > Subscriptions > example.com > (tab) Mail > (tab) Mail Settings > ( choose the desired domain with a click and choose the button ) Mail for Non-Existent Users

​

 

[davorg]

Hi UFHH01,

Thanks for your reply. In my original message I wrote:

In the Plesk control panel for the domain, I've selected "reject" in the non-existent users section of the mail configuration page. And I can see the domain listed in the /var/qmail/control/rejectnonexist file. And yet the spam emails are still accepted and the automated response emails are still being sent.​

So, yes, I know about that setting. And I have selected it. And yet, the bounce emails are still being sent. In the default .qmail file for the domain I can still see the "bouncesaying" command.

My question is not really "how do I reject email for unknown users?" but "why doesn't rejecting email for unknown users work correctly?"

Apologies if my original message wasn't clear.

Dave...

 

[davorg]

Reading further on this, I've found this section in "Life with QMail" - Rejecting Invalid Recipients During SMTP Dialogue which seems to imply that standard QMail doesn't support this functionality. So I'm left wondering why the Plesk configuration page promises a feature that it can't deliver.

Of course, that page is from 2007. It might be out of date by now.

 

[UFHH01]

Hi davorg,

which seems to imply that standard QMail doesn't support this functionality

Could you pls point out, which statements imply that?
Pls. be aware of the difference setting options "bounce" and "reject". Consider to use the command

/usr/local/psa/admin/bin/mchk --with-spam
or/and
plesk repair mail -y​

... if you experience issues with accepting eMails, even that above suggestions are set.


You can as well use the command:

mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa -e 'update Parameters set value="reject" where value="bounce";'​

to be sure that all Plesk DB - entries are correctly set to "REJECT", instead of "BOUNCE".

 

[davorg]

Could you pls point out, which statements imply that?

All of the solutions that it points to require patching and re-compiling qmail. So I'm happy to stand by my statement that standard qmail doesn't support it.

Of course, I have no way of knowing whether or not the version of qmail that is installed as part of Plesk has any of these patches installed.

Pls. be aware of the difference setting options "bounce" and "reject".

I'm well aware of that difference. I thought I was clear about that. I want qmail to reject email to unknown recipients, but it is still bouncing it.

Consider to use the command

/usr/local/psa/admin/bin/mchk --with-spam
or/and
plesk repair mail -y​

... if you experience issues with accepting eMails, even that above suggestions are set.

You can as well use the command:

mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa -e 'update Parameters set value="reject" where value="bounce";'​

to be sure that all Plesk DB - entries are correctly set to "REJECT", instead of "BOUNCE".

Thanks. I've tried all of those commands. But qmail is still bouncing the email, not rejecting it.

I guess I can set up an ignored mailbox and forward all unknown addresses to that. But I'd really rather get the rejection working.

Thanks for your suggestions.

Dave...

 

[TomBoB]

A bit of an unconventional idea...
Have you tried switching over to postfix for a short while and examine if the problem still occurs?
If the issue is gone, try switching back to qmail to further check if the issue comes back or if it stays resolved.

Just a thought
Tom