using office pro plus outlook version, but email is not on o365, it keeps going to o365 services!

users are using office pro plus, why does it always connects to office 365 email? (exchange online)

we are using the account only to activate outlook and the mail is hosted somewhere else, currently end users are not able to use outlook with their email hosted on another provider because it keeps going to office 365, now exchange online licenses is assigned though, only office pro plus and Teams