Microsoft is looking into a persistent Exchange Online outage that prevents users from sending emails and results in 503 errors on impacted servers. Users who are affected claim that emails received from Microsoft 365 environments are receiving “503 5.5.1 Bad sequence of commands” problems in response.
Some customers may have difficulty while sending Exchange Online emails and notice “Bad sequence of commands” warnings, the company acknowledged in the EX649175 ticket in the Microsoft 365 admin portal. Which Microsoft 365 locations are affected by this Exchange Online outage is still a mystery according to the business.
Customer reports indicate that consumers in the United States, Europe, India, and the United Kingdom are now feeling the effects, though.
A problem with Outlook.com that prevented users from searching their emails and caused 401 exception errors was also fixed by Redmond two weeks ago with the message, “Sorry, something went wrong. Please try once more later.