The performance of affected Microsoft Exchange Online Protection servers in UK South geolocation is now improving, we're not seeing any email delivery delays. A small number of emails sent by a subset of users in North Central US and West US geolocations may still be delivered with delays. Details of the incident may be found in SI# EX225938 on the Microsoft 365 Admin Dashboard and on Twitter: https://twitter.com/MSFT365Status/status/1324444676993277957
. Email signatures are added normally.