Method 1: Run Office 365 Support and Recovery Assistant. Use the I need help setting up my Office 365 email in Outlook diagnostic in the Support and Recovery Assistant (SaRA). Click Run when you are prompted by your browser. This diagnostic does automated checks and returns possible solutions for you to use to try to fix any detected issues.
I downloaded the EXE file. For me this is the weirdest download ever. It says at the beginning that it weights 41.5 Mb or something. Then, when you are almost there, suddenly it's more than that: now is 42.7, then when you are about to get this second limit, again the amount of data increases. This happens 25, 30 times!
Its seems you will never catch it! So at the end the whole deal was it's truly annoying.
This was for the former version, then it says. 'this is an old version, you must download this one'. I go and download that new one.
And it behaves exactly the same!! Once this new version was installed This is the most similar situation I have ever experience to the annoying 'You need to go to that other window and fill the form A3 then come back tomorrow and stand the queue again.'
Or the horse running after a carrot hanging from driver's stick. At the end it didn't help. A waste of my time. Just uninstall and install again. IT guys' way!