Question Spam Issue

[jakedawson]

Hey guys,
I am not super technical I am just looking for a hand. I have a Plesk server setup on digital ocean and my clients are having a major problem with spam. I have tried installing all the spam things and put it up to the highest spam protection but it makes no difference. Where to next?
I got someone to have a look and they said it was a bug and they had to reinstall. I am not keen to do that as I am sure it should be fixable.

Regards,
Jake Dawson

 

[Bitpalast]

"highest spam protection": To me it sounds like a frequent error we see with many of our customers. They normally think that the higher the value, the better the protection. But SpamAssassin's "Spam Filter Sensitivity" field does the opposite: It is a threshold. So "high protection" asks for a low value like "2" in that field, so that if an incoming mail reaches >2 points in spam assessment, it will be considered spam. Could that be the same issue in your installation?

 

[jakedawson]

No i have it set as low threshold (highest i think)

 

[Bitpalast]

To check whether you found a bug or not, you could look into /var/log/maillog (CentOS, Redhat) (/var/log/mail.log on Debian/Ubuntu) for an incoming spam mail what the spam filter does with it. Specificially the score that it gets. If there are not technical issues, but the score of an incoming mail is simply low enough so that it passes the filter, your only option is to apply additional spam fighting methods, e.g. incoming mail filters in your e-mail client software.

 

[Kaspar]

Also, may I suggest you check to following mail settings that help reduce spam.

In Plesk go to Tools & Settings > Mail server settings and make sure the following options are enabled:

DMARC
> Enable DMARC to check incoming mail

DKIM spam protection
> Verify incoming mail

SPF spam protection
> Enable SPF spam protection to check incoming mail
> SPF checking continues when there are DNS lookup problems
> Reject mail when SPF resolves to "fail" (deny)

Turn on spam protection based on DNS blackhole lists
You could use the following lists: b.barracudacentral.org;sbl.spamhaus.org;xbl.spamhaus.org;bl.spamcop.net;psbl.surriel.com;spam.spamrats.com