So far Friday the 13th has yielded 2 power cuts in our main data center. No big deal, I guess, except for the fact that the company we use to filter/scan our email happens to be moving their backup/secondary MTA today. Oh, and that company? They share offices with our Infrastructure company, and they lease some space in our data center too. So their primary + secondary MTAs were dead, meaning a lot of mail was flat out rejected instead of being queued (and they don't really know why either).
Given that it's Friday the 13th, I guess we got off lightly so far. Still a few hours to go yet.