Those of us who run their own mail servers: what is your MTBF? That is, ignoring all other differences, from the standpoint of pure availability, how do you compare to popular centralized email services?
Just asking.
Just asking.
Other than that, thirty minutes downtime 14 months ago when the public-facing redundant routers mis-detected a failover, failed STONITH and entered split-brain status.
I wouldn't commit to better than 99.9% with our infrastructure (single datacenter with remote data backups) but we exceed the metric most years (99.99% in all but one of the last ten years).
I can't recall the last unplanned outage since the 2008 one.