I have to make provisioning between Azure AD and GTM working. To accomplish it, I have to 'Authorize' this connection in Azure AD.
The problem is, that when I enter service admin account credentials (in 'Authorize' login form), GTM wants me to enter verification code (which should be sent to email address of given service account), but no email is ever received.
I looked to mail flow logs in our O365, but there are no sign, the email was received/blocked/whatever. I checked, that emails sent to service account from my personal gmail are received succesfully, also service account can login to GTM admin web interface.