This incident has been resolved.

A fix has been implemented and we are monitoring the results.

We had an issue with submission notifications going down around 0:00 UTC today. We re-enabled those submission notifications around 1000 UTC, but that has caused a delay in submission processing and notification delivery. As a result, processing of direct XML submissions either manually uploaded or posted to doi.crossref.org and submissions via our web deposit form - https://apps.crossref.org/webDeposit/ - are delayed. Our system is working through the backlog at the moment. -IF