To configure your device or application, connect directly to Microsoft 365 or Office 365 using the SMTP AUTH client submission endpoint .Įach device or application must be able to authenticate with Microsoft 365 or Office 365. This option supports most usage scenarios and is the easiest to set up. For more information, see Enable or disable authenticated client SMTP submission (SMTP AUTH) in Exchange Online. SMTP AUTH is disabled for organizations created after January 2020 but can be enabled per-mailbox. You must also verify that SMTP AUTH is enabled for the mailbox being used. For more information about OAuth, see Authenticate an IMAP, POP or SMTP connection using OAuth. As a result, there are no plans to disable Basic Authentication for SMTP AUTH clients at this time.
Although SMTP AUTH now supports OAuth, most devices and clients haven't been designed to use OAuth with SMTP AUTH.
We recommend using Modern Authentication when connecting with our service. This option isn't compatible with Microsoft Security Defaults.
