Re:list of many spam fighting techniques (Score 1)

For those of you who have used managed services to fight spam - has anyone had any issues with the reliablity of an anti-spam managed service? I heard that Postini was recently down for 12 hours! Not only did it take down all of their spam filtering services, but it also prevented all email from coming through! They claim 99.999 percent reliabilty. Last I checked five nines of uptime meant no more than 5 minutes of downtime a year. Has anyone had the same experience with Postini or other anti-spam services? "