UPDATE – 9:40am ET
Sites should begin receiving acknowledgements over the next several hours for returns waiting for an ack. There is no need to resubmit impacted returns.
9:28am ET
We have received some reports of returns filed 3/27/18 that have not received an acknowledgement from the IRS as of yet. We are currently looking into what the issue may be. At this time, we ask that sites with returns waiting for an acknowledgement do not resubmit. This post will be updated once we have additional information to provide.