I have noticed that UVM Appliance and BeyondInsight email notifications do not support communicating with SMTP servers that require Strict StartTLS. Upon investigation, it appears that the Email Notification feature is built on the System.Net.Mail (SmtpClient) library, which is legacy and does not support Strict StartTLS.

Has anyone encountered this scenario where SMTP communication is restricted to Strict StartTLS in your environment? If so, what solutions or workarounds have you found?

Additionally, does BeyondTrust have any plans to migrate to the MailKit SMTP client, which Microsoft recommends as a modern replacement for System.Net.Mail?