How can I drop all email globally above a certain spam score?

To create a global sieve filter that will drop all email over a certain spam score follow the directions below. This method works on Plesk 12.5, Plesk 17.X ,and Plesk 18.X. Note: These instructions are for servers running Dovecot. They will not work if your server is using Courier-imap.

Create a new global sieve filter:

su root
mkdir /etc/dovecot/conf.d/custom-sieve
cd /etc/dovecot/conf.d/custom-sieve
nano /etc/dovecot/conf.d/custom-sieve/global_after.sieve

Add the following code or any other sieve rules, in the above  file. Note: each * corresponds to 1.0 point of the spam score. So if you want to drop email with a spam score of  15.0 or higher you would change the X-Spam-Level to 15 stars like "***************" We recommend not setting this any lower than 15 stars at first to make sure that you don't discard any valid email.

if anyof (header :contains "X-Spam-Level" "***************")

Create the new global sieve configuration directive for Dovecot (the 37 order is important):

nano /etc/dovecot/conf.d/37-custom-global-sieve.conf

Add the following code to that file:

plugin {
sieve_after = /etc/dovecot/conf.d/custom-sieve/global_after.sieve

Run the sievec command to compile the new sieve (important):

sievec /etc/dovecot/conf.d/custom-sieve/global_after.sieve

Restart the SpamAssassin and Dovecot services:

service spamassassin restart
service dovecot restart

To verify the filter you can send a test spam message to the email as described here :. You will see entries like this in the mail log when a message goes over the limit you set and is discarded:

Jul 28 07:26:13 el7p17 dovecot: service=lda,, ip=[]. sieve: msgid=<>: marked message to be discarded if not explicitly delivered (discard action)
Jul 28 07:26:13 el7p17 postfix-local[94765]: message discarded by a mail handler

Note: This will run your custom global sieve filter(s) after any other personal filters each account may have. To disable the global filter(s) for any individual accounts, simply add a new personal filter (in your Roundcube or other webmail client) that hits on all emails and simply has "Stop processing filters" as its only action.

Credits go to G J Piper in the Plesk forums for this solution.

  • drop, sieve, reject, score
  • 2 Users Found This Useful
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