Microsoft 365 is highly utilized by numerous organizations. Please integrate OAuth for Microsoft 365 within WHMCS for us to be able to provide a more secure way of authentication and remove unsecure SMTP legacy clients.
OAuth with SMTP AUTH is a must in today’s business environments.
Version 8.6 has now reached public beta, which includes OAuth2 Support for Microsoft Email Services, for both sending and importing: https://blog.whmcs.com/133721/whmcs-86-beta-now-available
Please join us during the pre-release testing period and provide your feedback in our dedicated beta community board: https://whmcs.community/forum/590-whmcs-86-beta-discussion/