I faced once with the same problem after installing evolution-ews.
But after I've tried to add account 3-4 times and it worked.
I removed unnecessary accounts and left the only one.
But there is another problem. Evolution hangs and freezes
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
Evolution appears unable to create EWS or Exchange MAPI account
To manage notifications about this bug go to:
ubuntu-bugs mailing list