Option 1 (recommended): Authenticate your device or application directly with a Microsoft 365 or Office 365 mailbox, and send mail using SMTP AUTH client submission
Note
This option is not compatible with Microsoft Security Defaults or multi-factor authentication (MFA). If your environment uses Microsoft Security Defaults or MFA, we recommend using Option 2 or 3 below.
You must also verify that SMTP AUTH is enabled for the mailbox being used. See Enable or disable authenticated client SMTP submission (SMTP AUTH) in Exchange Online for more information.
This option supports most usage scenarios and it's the easiest to set up. Choose this option when:
-
You want to send email from a third-party hosted application, service, or device.
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You want to send email to people inside and outside your organization.
To configure your device or application, connect directly to Microsoft 365 or Office 365 using the SMTP AUTH client submission endpoint smtp.office365.com.
Each device or application must be able to authenticate with Microsoft 365 or Office 365. The email address of the account that's used to authenticate with Microsoft 365 or Office 365 will appear as the sender of messages from the device or application.
How to set up SMTP AUTH client submission
Enter the following settings directly on your device or in the application as their guide instructs (it might use different terminology than this article). As long as your scenario meets the requirements for SMTP AUTH client submission, the following settings will enable you to send email from your device or application.
| Device or Application setting | Value |
|---|---|
| Server/smart host | smtp.office365.com |
| Port | Port 587 (recommended) or port 25 |
| TLS/StartTLS | Enabled |
| Username/email address and password | Enter the sign in credentials of the hosted mailbox being used |
