This article is a collection of various guides that outline the options you have available to reduce the amount of spam that arrives at the inbox of your cPanel email accounts.
This guide covers a large number of options available to you. It is NOT required to implement all of these options to have a spam-free experience on cPanel. Each of the individual options listed here would only be enabled to meet your specific spam protection needs.
1. Enable BoxTrapper
This may be among the most easily implemented and effective methods for preventing spam from arriving in your inbox.
2. Teach Spam Assassin How to Identify More Spam
This method requires some custom configuration from a systems administrator, as well as active participation from the end-user. This means that you must train the end-user how to teach Spam Assassin about their specific spam. However, this extra effort does a lot to effectively identify spam messages that may be using more clever techniques for bypassing the widely avaialble spam filters for Spam Assassin.
3. Reject messages over a certain size
If you find that the majority of problematic spam that you are getting is over a certain size, and the majority of legitimate messages are under that size, you have the ability to configure your server to reject messages over that size threshold.
4. Adjust the weight of individual SpamAssassin rule scores server-wide
If you find that certain incoming spam messages are getting through, but adjusting the weight of a specific rule would help, the following guide explains how to adjust these rules for the entire server:
5. Adjust the weight of individual SpamAssassin rules on a per-account basis
If the incoming spam issue is isolated to a single cPanel account, and you do not want to adjust the weight of a SpamAssassin rule for the entire server, you can use the following guide to accomplish this:
6. Add an additional custom SpamAssassin ruleset that better fits your server's needs
You have the option to install custom SpamAssassin rulesets if you find one that will aleviate a problem that you're having with spam.
7. Create Custom rule sets for SpamAssassin
If you have the technical skills and motivation to do so, it is possible to craft your own custom rules for SpamAssassin. Please keep in mind that cPanel is not able to provide support for the creation, installation, use, or maintenance of these custom rulesets.
8. Edit the default SpamAssassin score required to mark a message as spam server-wide
If you find that all legitimate mail on the server scores much lower than the current default SpamAssassin score threshold, and some spam messages are also scoring lower than the current default, you can use the following guide to adjust this setting. However, as a general rule, setting the score lower than the default will end up marking more legitimate mail as spam. Lowering this setting is usually only advisable if you have done extensive training for SpamAssassin from Option 2 listed above and you notice that all legitimate mail scores very low.
9. Edit the default SpamAssassin score required to mark a message as spam on a per-account basis
This has the same effect as option 8 above, but it is limited to an individual account.
10. Block messages by subject server-wide
If you find that a common subject is used for spam messages that are making it through to the inbox, you can block these subjects for the entire server with the following guide:
11. Filter incoming emails by country
If you find that spam is mainly coming from a specific country that your clients do not interact with, you can block those messages with the following guide:
12. Block all incoming emails that originate from a specific domain
If you find that a specific domain is sending a large amount of messages to your server you can block that domain with the following guide:
13. Enable the default or a custom Remote Block List (RBL)
14. Stop using BackupMX servers or implement a custom spam protection system on those BackupMX servers if you are using BackupMX
The following are some other general guides related to Spam Assassin in Spam in general: