We have been using a SpamTitan (http://www.spamtitan.com) virtual machine for approximately a year now and it works very well. I bought the license for up to 100 users, downloaded the VMware virtual machine image and converted it to run on ESX server. Highlights:
* The interface is very impressive and setup was quite straight forward - no reading of the manual required.
* Uses two anti-virus engines: Kaspersky and ClamAV
* Uses OCR to detect image-spam
* Multi-layer anti-spam approach - scoring from several algorithms is compiled to provide a single spam score.
* The product checks for valid recipients (including aliases) against my Exchange server.
* Logging and reporting are excellent.
* There have been some false positives and initially it didn't block as much spam as I had hoped but as the Bayesian analysis has improved so have the detection rates.
* Afraid of false positives, I initially monitored the quarantine and white listed many of the the domains belonging to suppliers and clients.
* I am not yet sending outgoing mail through my SpamTitan but this would improve the filters as well using what they call "PenPal bonus".
* After a version upgrade, the ClamAV definitions were no longer being updated. I contacted support and they connected from remote (via a tunnel I opened) and fixed the problem. An excellent support experience.
* The users control their own experience - I have configured it to send each user a daily digest of mail that has been quarantined since the previous report. Each user then manages their own quarantine, white list, etc. Training has been minimal and response has been very positive.
I was surprised to find that we are averaging only approximately 12% legitimate mail.
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We have been using a SpamTitan (http://www.spamtitan.com) virtual machine for approximately a year now and it works very well. I bought the license for up to 100 users, downloaded the VMware virtual machine image and converted it to run on ESX server. Highlights:
* The interface is very impressive and setup was quite straight forward - no reading of the manual required.
* Uses two anti-virus engines: Kaspersky and ClamAV
* Uses OCR to detect image-spam
* Multi-layer anti-spam approach - scoring from several algorithms is compiled to provide a single spam score.
* The product checks for valid recipients (including aliases) against my Exchange server.
* Logging and reporting are excellent.
* There have been some false positives and initially it didn't block as much spam as I had hoped but as the Bayesian analysis has improved so have the detection rates.
* Afraid of false positives, I initially monitored the quarantine and white listed many of the the domains belonging to suppliers and clients.
* I am not yet sending outgoing mail through my SpamTitan but this would improve the filters as well using what they call "PenPal bonus".
* After a version upgrade, the ClamAV definitions were no longer being updated. I contacted support and they connected from remote (via a tunnel I opened) and fixed the problem. An excellent support experience.
* The users control their own experience - I have configured it to send each user a daily digest of mail that has been quarantined since the previous report. Each user then manages their own quarantine, white list, etc. Training has been minimal and response has been very positive. I was surprised to find that we are averaging only approximately 12% legitimate mail.