"STARTTLS is required to send mail" from Office365 to EV SMTP archive
We have setup SMTP journaling on EV 14 and are getting this error when we attempt to validate the connector from O365. On the EV server, we do have a certificate installed and port 25 (as per the EV docs) is open. How can we resolve this?
Thank you for your suggestions. We have been using Enterprise Vault for almost 15 years now, however the SMTP archiving is a new feature to us. In this case, the problem turned out to be that we have the RC4_HMAC_MD5 encryption type disabled in our domain (as per CIS recommendations). Once that cipher was enabled, then we could send messages to the SMTP server created by Enterprise Vault. It should be noted that that cipher is recommended to be disabled by the Center for Internet Security https://www.cisecurity.org/, so anyone changing this setting (in order to get SMTP archiving to work) is creating a deviation to the recommended benchmarks