Hi @shanekryme ,
Apologies for the delay in replying. For FluentSMTP, you should not choose Single tenant for this setup.
Instead, we recommend selecting Any Entra ID tenant + Personal Microsoft accounts. This is Microsoft’s current wording for what was previously called the Multitenant + Personal Microsoft accounts option.
FluentSMTP’s Microsoft mailer currently uses Microsoft’s /common OAuth endpoints, so it is designed to work with a multitenant-style app registration rather than a tenant-specific (single-tenant) application.
If you’re only using a Microsoft 365 work or school mailbox, Any Entra ID tenant may also work. However, Single tenant is not the recommended option for FluentSMTP’s default Outlook/Microsoft 365 connection flow.
Also, please make sure the following settings are configured correctly:
- Platform: Web
- Redirect URI:
https://yourdomain.com/wp-json/fluent-smtp/outlook_callback
If authentication still fails after making these changes, please share the exact error message or a screenshot, and we’ll be happy to guide you further.
Thank you.