How to modify your spam settings using Plesk

Plesk’s SpamAssassin settings control how incoming mail is classified as spam. This guide covers the server-wide settings, which require administrator access rather than an ordinary reseller or mailbox login.

Adjust server-wide filtering

1. Log in to Plesk as an administrator.
2. Open Tools & Settings > Spam Filter, under Mail.
3. Check Switch on server-wide SpamAssassin spam filtering, or the equivalent Turn on option on Windows.
4. Review The score that a message must receive to qualify as spam.
5. Enter the intended threshold and click OK.
6. Reopen the settings to confirm the value.

A lower threshold classifies more messages as spam and can increase false positives. A higher threshold is less strict and may allow more unwanted mail through. Record the existing value before changing it.

Check the result

Review legitimate mail and spam over a representative period. Check how suspected messages are handled; classification does not always mean deletion.

If you need to change only one mailbox, use its Spam Filter settings where the provider permits individual configuration. Do not change server-wide policy merely to adjust a single mailbox.