To reduce incoming spam in a Plesk Server, please follow the steps below:
1. Enable SpamAssasin for all domains as given below
Go to Plesk >> Sever Management >> Tools & settings >> Spam Filter Settings
Click "Switch on server-wide SpamAssassin spam filtering"
Unclick "Apply individual settings to spam filtering".
This will force the SpamAssassin feature for all email accounts. If you choose to enable "Apply individual settings to spam filtering", you can go to the properties of each email account & enable spam filtering.
Finally, press OK
2. Enable DNS Blacklist as given below.
Go to Plesk >> Sever Management >> Tools & settings >> Mail Server Settings
Tick "Switch on spam protection based on DNS blackhole lists"
Add following in the box alongside.
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bl.spamcop.net;sbl-xbl.spamhaus.org
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Finally, press OK
This will ensure that spam emails from known spamming servers are blocked in server.
