Microsoft deprecated basic authentication in Exchange Online on 12/31/2022 per:
https:// learn.microsoft .com /en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online
This is a feature request for Matomo to support OAuth or Graph API for communicating with an SMTP server.
See https:// www.xpectoitsolutions .com /microsoft-office-365-smtp-integration-for-website-contact-forms-2026-guide–oauth-20–graph-api
Thank you