As an Exchange Admin, you have deployed Exchange 2016 in your environment. The time comes for testing and you find that you are unable to setup an IMAP account as it fails when trying to send the email on the final step:
- “The account ‘Domain\Account’ provided valid credentials, but it does not have submit permissions on SMTP Receive connector “Receive Connector”….”
To fix this, open up the Exchange Admin Center (EAC) and go to your mail flow tab and click on receive connectors. Look for the connector in question mentioned in the error and edit it.
Navigate to the security tab and then tick “Exchange Users” and then click Save.
Give it a few minutes to take effect and then try and setup the IMAP account, this time it should succeed without error.
Hope it helps.