Email policies of HOSTALIA
Qmail plugin to rate limit emails sent by an email address
This plugin, developed by Hostalia, uses MySQL to store the MAIL FROMs that Qmail receives, so a rate limit can be done.
When the email amount sent by an address is bigger than the value that is set, the mail is rejected.
Each hour, the table records are deleted so the limit is for one hour, for example, 100 messages per hour and email address. Individual limits can be done, too.

You can download it from:

Qmail must be patched with SPP.

RBL checker
Check if your IP address is listed on the most used RBLs:


Patch for razor2
Vipul's Razor is a distributed, collaborative, spam detection and filtering network, as is said in their website. With this patch, you can whitelist some fingerprints as the documentation says (this feature isn't supported from razor1).
You can download the patch from