intertwingly

In an attempt to reduce spam, I'm now rejecting any email comments that are addressed to weblog entries which are over 30 days old.  Implementing this only took a few minutes work, but required me to break a few abstractions in my implementation.  Undoubtedly, this will get cleaned up in a refactoring, but a review of the code reveals a number of related items:

• I use SpamAssassin to route based on content and headers
• I'm specifically blocking two IP addresses from which I got persistent spam.  These seem to be open SMTP relays.
• Age of target blog entry is now used to reject comments

Each is based on exploiting a fundamental characteristic of SMTP: namely that it is a protocol that enables without obscuring.