Released: April 2021 Exchange Server Security Updates

@Lyle Epstein Hi there, thanks for your comments, for us Outlook stopped working, everyone's Outlook showed "Disconnected.", and no matter what we did, it wouldn't connect.  There may have been other parts of the system that also weren't functioning, but mailflow and OWA seemed ok, as that's what we had to use temporarily.  I'm still waiting for the full RFO from our 3rd Party and Microsoft, but looking at the current certificates, this one was replaced, 'Issuer : CN=Microsoft Exchange Server Auth Certificate, NotBefore : 15/04/2021 21:52:13'. Our email didn't start working again until 4:01am on the 16th, so I don't think this was the only work that was carried out to fix it. I'm not looking forward to May's updated! ;o)