Documentation for SpamAssassin rules (HTML_30_40)

Question

I'd like to refine the password reset mails which are sent by my web application to avoid them to be mistaken as spam; a customer forwarded a mail header to me which contains several SpamAssassin rule names.

Some of the rules I could find, e.g. BAYES_40, but others I couldn't find there; those are:

• HTML_30_40
• TO_NO_BRKTS_HTML_ONLY
• TO_NO_BRKTS_NORDNS
• TO_NO_BRKTS_NORDNS_HTML

What do these rules mean; are there documentation pages somewhere? The SpamAssassin which reported them is version 3.3.2; the latest version as of now is 3.4.1. Do those rules still exist?

Answer 1

The HTML_30_40 rule is no longer included in SpamAssassin, but if I remember correctly it was some test that concluded the email consisted of 30-40% HTML codes. Why that has any relevance for spam filtering I cannot see, and probably that is why it is no longer present.. :)

Those other rules still exist in SpamAssassin version 3.4.1. There is no explicit documentation per rule, other than an occasional comment or description along the rule implementation itself:

describe   TO_NO_BRKTS_HTML_ONLY       To: misformatted and HTML only
describe   TO_NO_BRKTS_NORDNS_HTML     To: misformatted and no rDNS and HTML only

You are probably sending emails from an ip-address with no reverse-DNS name, and the To: line is poorly formatted. Things should improve significantly if you get the DNS problems fixed (or relay the emails via your ISP) and format the To: line in the email properly, e.g.

To:  "J Random User" <jrnd@email>