On Sat, Jan 21 FedEx is scheduling a maintenance of the production servers that will result in a shipping rate API outage from 10pm EST until midnight (2 hours total).
Starting at the same time there will be a tracking API outage from 10pm EST until 4am next morning (6 hours total).
Sorry for the very late notice on this announcement, we actually completely missed any notification of it coming. We're not sure exactly what their current status is as it is well past their maintenance window and rate requests still appear to be offline. We'll post more as we find it.