I see an error when trying to login using an Outlook account: Account does not have a valid mailbox

You may get this error in case you’ve just created a new Outlook account (or an alias) or have not used it for a long time. In such a case, the solution is to log into your account using a normal web browser and try and use your account (i.e. send an email, receive and email etc). Then try logging into 2Do again.