smtpfilter is a filter for an SMTP session which passes the session through transparently in real time, except for the DATA command which is intercepted in order to scan the data for spam and/or viruses with the scanner of your choice.
If you are reading this source, it is what should have been an internal release and consequently has a few comments at the head of the file which would not normally be here. Most likely I must have released this in a hurry because someone needed some
recent feature that has been added, before I had time to do a periodic code review and tidy-up. If this is your first time looking at or installing this code you should probably get in
touch with the author (firstname.lastname@example.org) and ask for a cleaner version before you start.
The descriptive comments which explain what this program does, and how, have slowly migrated from being at the top of the file to being lost half way down. That is something which will be done in the next maintenance release.
But this version *does* work, and works very well now. It is in service at the University of Texas Pan American, with 2000 staff and 15,000 students (although not all of those are active emailers -maybe only 2000-3000 are in heavy use. It sometimes looks like
AOL and MSN and Yahoo are the official campus mailers.