cPanel includes SpamAssassin, a powerful spam filter that scores incoming emails and can automatically delete or move spam to a junk folder.
Enabling SpamAssassin
In cPanel, go to Email > Spam Filters (or Apache SpamAssassin). Toggle the filter on. You can enable Spam Box to move spam to a separate folder instead of deleting it outright β recommended initially so you can check for false positives.
Adjusting the Spam Threshold
SpamAssassin gives each email a spam score. The default threshold is 5 β emails scoring 5 or higher are treated as spam. Lower the threshold for more aggressive filtering or raise it to reduce false positives. A threshold of 4β6 suits most users.
Whitelist and Blacklist
Under Additional Configurations, you can whitelist senders (so their email is never filtered) or blacklist senders (always marked as spam). Format: user@example.com or @example.com for entire domains.