I am having the same error message suddenly come up saying this account cannot be used with outlook because I am currently signed into 365.  I have read through and tried all the suggestions.  As far as I can tell this has been an ongoing problem and Microsoft does not appear to know how to fix it.  This is unacceptable.  It is absolutely imperative that I can access my email account asap as very important, time-sensitive information is waiting for me.  PLEASE HELP!!!!!!!

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