VentureBlog has an interesting bit on spam, claiming that spam is going to give Microsoft control over the entire email server market. The logic is kind of interesting; basically it boils down to using your Exchange server license as a bond against sending spam. If you spam, they yank your license, so owning a valid Exchange server license is an automatic key to spam whitelisting:
However, corporations are already shelling out big bucks for email - specifically for Microsoft Exchange or IBM/Lotus which between them have 75% of the corporate market.
Microsoft could just provide a stamp on each outgoing message (think public key cryptography) identifying that it came from a specific exchange server. This would be verified with Microsoft, which would provide a whitelist of valid exchange servers to every anti-spam company. [VentureBlog]
Three problems with this:
- Bayesian filtering seems to work really well. My home email filter is over 99% effective right now, blocking roughly 200 messages per day with no false positives.
- Spammers are already using viruses to generate open relays. How long will it take before office computers are attacked deliberately to use their whitelisted Exchange server for spamming?
- The liability issues of point 2 will effectively keep Microsoft from blacklisting large customers, even when bushels of spam are pouring out of their servers.
So, in short, I think it's a neat idea, and I wouldn't be surprised if Microsoft tries it, but it isn't going to help. In fact, it'll probably just make corporate PCs even more attractive to spammers.