Over the past two days, /var filled up, preventing new email messages from being accepted by the server here. I've corrected the problem, and as messages queued on other servers are retried, they should start trickling in here shortly. If you normally have a decent volume of mail to your account here, some of it may come in big chunks now that things are back online. I apologize for the interruption in service, as I should have caught that earlier but I've been busy with the holidays.
As to the root cause, it was the apache error log filling up very quickly with deprecated and strict code warnings. Even though these are disabled in the default config, several users appear to have code the explicitly turns some of this extra logging back on, and thus fills up the log faster than usual. If you have a site here, now would be a good time to see if it's generating errors and update any third-party scripts you have installed to ones compatible with php 5.4. Not a big deal at this point though, I'm just going to rotate the error log more frequently.