Resolved Spam black list not working

[David Jimenez]

We have an email address that is just a forwarder. Plesk allows us to turn spam filtering on for that forwarder. In advanced settings, we have added MAILER-DAEMON@* to the blacklist as someone is spoofing that email address in their spam blasts.

However, even after adding the black list, the forwarder continues to send through MAILER-DAEMON@* type emails. Any suggestions or does this function not work even though it is an option in Plesk?

 

[David Jimenez]

So, I did a server-wide spam blacklist on *@*.ru, which is where almost all of the MAILER-DAEMON stuff is coming from. It is still coming through. So, I guess Plesk's settings for spam blacklists do not work or wildcards don't work as described. (also added it direct to the advanced settings for the forwarder)

 

[David Jimenez]

I've come to the conclusion that spam blacklists must not work with qmail. I have blacklisted MAILER-DAEMON@* on SpamAssassin for the entire server and on the advanced spam settings for the forwarder and the receiving email account. None of these stop the incoming emails.

 

[Bitpalast]

Your blacklist probably does not work, because the mail is not delivered to a mailbox, but forwarded. Normally mail that is forwarded is not processed by anti spam tools, but forwarded "as is". That is by design, it is not an error. When you deliver mail to your local mailbox, spam filters will be active and blacklists will probably work. Could you please test whether the mails are blocked when you do not forward them, but deliver them to a local mailbox?

In general, it is a very bad idea to forward all incoming mail to another address. The reason for that is that this does forward all incoming spam, too, and many big A providers will record that YOUR server is sending spam to one of their accounts. They do not look at the origin of the mail, but at the last server in a chain of SMTP servers that was forwarding the spam. Sooner or later they will blacklist your IP, because they have recorded all the spam coming from your IP. It does not matter that you are not the source of that spam. From their perspective your server is.

Instead of forwarding you should use a POP3 collection service. Here is an (incomplete) list of these services for some widely known providers:

T-ONLINE
Set-up mail collection | 3

GMAIL
Collect mails from other accounts - GMail support

GMX
Set-up mail collection - GMX support

WEB.DE
Sammeldienst: E-Mail Import aus altem Postfach ins WEB.DE Postfach - WEB.DE Hilfe

OUTLOOK.COM (hotmail.com etc.)
Add your other email accounts to Outlook.com - Outlook

 

[David Jimenez]

The forwarding email account forwards to an account with the same domain on the same server. That ultimate email account has the same blacklist settings. Nothing is marked ***spam*** by SpamAssassin and the delete spam settings on both the forwarding account and ultimate account do not delete the blacklisted items.

 

[David Jimenez]

I have been told that even though the emails of interest are coming from something like MAILER-DAEMON@<someonesdomain>.com, the are treated as if they are messages generated by our mail server. Thus, they don't go through the spam filter at all. Oh well.