efficient / effective use of Email Filtering ??


Dec 11, 2008
Hi folks -

I just discovered email filtering, and am having a fun time directing spam to my junk folder.

On the User Level Filtering page (User Level Filtering), the Best Practices section recommends:
.. using multiple, simple filters instead of a single, monolithic filter. Exim, your server's mail
transfer agent, handles many small rules much more efficiently ...​
What's a reasonable number of conditions? For example, there are a whole slew of obvious
marketing terms that, if contained in the Sender field, almost certainly signify a junk message.
Are 5 conditions in a single rule reasonable?
(e.g. Sender contains <obviousMarketingTerm1> or <obviousMarketingTerm2> ... or <obviousMarketingTerm5>)
10? 20? Alternately, how many is too many?

Also, presumably when I create a filter, there's a config file that's created somewhere.
Can that be edited directly? Might that be more efficient than using the UI?

Any & all insight welcome.

Thanks kindly,

- Richard
Last edited:


Staff member
Apr 11, 2011
Hello :)

Using five conditions in a single rule should be fine. However, it's better to setup a filter, and then test it to see the results.

Here is a post on where the user level filters are stored if you want to edit them manually:

cPanel - User Level Filters

Thank you.