I'm going to bump this a year later - it especially makes sense for people on the SMB or SOHO plans.

Last time this was discussed, I do believe I remember them saying something about their licensing agreement with Arm Labs stated that they could only use their license(s) with their implementations. I could be wrong though. 

Bumping this again too- when I talked to the MessageSniffer folks a long time ago, I didn't get the impression there was any reason we couldn't use the existing license, just that SmarterTools didn't implement a way to do it. Would be great if we ST would implement this, even though I know it'd mean a few bucks less commission for them.