Office 365 XOAUTH2 for IMAP and SMTP Authentication fails

Question

Recently the support for OAuth 2.0 for IMAP and SMTP in the Exchange Online has been announced. Following the guide I\'ve set up the application permissions and IMAP and SMT

Answer 1

Other responses already point out: although you can simultaneously authorize unrelated scopes at the /authorize endpoint, each call to the /token endpoint may involve only a subset of related scopes.

The question and several responses also raise the following issue: Should the scopes for IMAP/POP/SMTP be prefixed with https://graph.microsoft.com/ or https://outlook.office365.com/ or what? In fact, Microsoft documents that the scope names should be prefixed with https://outlook.office.com/:

Protocol  Permission scope string
--------  -----------------------
IMAP      https://outlook.office.com/IMAP.AccessAsUser.All
POP       https://outlook.office.com/POP.AccessAsUser.All
SMTP      https://outlook.office.com/SMTP.Send