What is ORFilter?
ORFIlter (Open Relay Filter) started as an Open Relay Filter based on RBL's (Real Time Blacklists) for Microsoft Exchange Server. As this is still the main functionality, I've added more features over time, like keyword filtering, SURBL, and custom black and white lists. ORFilter operates on your mail server, not on your mail client. When detecting / suspecting a spam message, it's depending on the score, either deleted, redirected or let through with an altered subject.
Main functionality
- Support for unlimited number of DNS based blacklists as ordb.org or spamcop.net
- Support for unlimited number of SURBL like blacklists as surbl.org
- Black and white lists (based on IP or SMTP address)
- Custom bad / good word list
- Scoring system
- Sending rejection message
- Redirecting to spam mailbox
- Subject line tagging
- Adding X-ORFilter header to trace why a message is recognized as spam
- Logging
- Higly controlable, logging
- Very active user forum (currently down)
- Catches 95% of all spam
- FREE
Supported Operating Systems
- Windows 2000, SMTP server or Exchange Server 2000
- Windows 2003, SMTP server or Exchange Server 2000 and 2003
- Windows XP
What's the catch
ORFilter is completely free (no catches, no commercials added to your mail etc etc). There are a few things you can do to keep the project alive:
Use the forum to register, post questions, bugs, suggestions and maybe answers to other's questions
Spread the word, make links to this site
Donate some money directly using PayPal. I really appreciate when people make a small donation. So far, the donations not even pay for the hosting costs of the website :( Many thanks for the people who did make a donation! If you make use of freeware and it is good for you, be good for the programmer that has spend many hours of free time. Thank you!