My Exchange server is not receiving emails from GMAIL. I ran a checktls report for receiving emails and the gmail sender gets an error- "TLS Negotiation failed: generic::failed_precondition: starttls error (0): protocol error"
A test on checktls fails with errors:
-Cannot convert to SSL (reason: SSL connect attempt failed)
-Cannot proof email address (reason: MAIL FROM rejected)
I removed the IP Blacklist providers, and antivirus and that did not help.
Just not sure how to troubleshoot further and resolve.
I use a wildcard certificate in Exchange could that be the issue?
Help will be appreciated.