We've covered the outages at Google pretty regularly, so when they released some metrics on email reliability it only seemed fair to tell their side of the story. According to the graph and summary posted on the official Google blog, Gmail had less unplanned downtime per month than Groupwise, Lotus, or Exchange. And when those companies planned downtime is also taken into account, of which Gmail had none, the difference in downtime nearly doubled in every case.
These numbers help to reinforce what many analyst have stated earlier -- that Google's high profile puts undue pressure on their SaaS offerings, which when compared with traditional software are extremely stable. Google also announced they will guarantee future reliability for more of their SaaS products -- saying they will, "extend the 99.9 percent service level agreement we offer Premier Edition customers on Gmail to Google Calendar, Google Docs, Google Sites, and Google Talk. We have been delivering high levels of reliability across all these products, so it makes sense to extend our guarantees to them."
For more info check out the full posting on the Google Blog. Also, if you have any SaaS or Enterprise 2.0 news of interest, please email it to me, Jason Hinkley, at Jason (at) ebizQ.net.