Microsoft 365 is a software offering that bundles Office 365, Windows 10, and EMS (short for Enterprise Mobility + Security) The Microsoft 365 online productivity suite experienced multiple outage issues throughout the last two days. Users reported that they couldn’t access their mailboxes through multiple protocols. Some users also reported slow e-mail sending and receiving (with more than 3-hour delays), missing e-mails, as well as sending or receiving multiple repeated emails at one time. Microsoft responded with the following statement: “We re working to resolve difficulties a limited subset of enterprise customers in Europe are experiencing when attempting to access Exchange Online”””
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-365-suffers-massive-two-day-outage-outlook-and-exchange-down/