We have a mail firewall to scan emails before it can be delivered to the mail server. We have two different mail server systems, one is SmarterMail, one is cPanel Courier. From the mail firewall log, it seems the firewall cannot verify the recipients on Courier, but it has no problem on SmarterMail. Any idea what's the problem? Thank you.


Here is the log in mail firewall:

Sep 30 09:23:23 xxxx sm-mta[32051]: STARTTLS=client, relay=xxx.xxxx.com., field=cn_issuer, status=failed to extract CN
Sep 30 09:23:23 xxxx sm-mta[32051]: STARTTLS=client, relay=xxx.xxxx.com., version=TLSv1/SSLv3, verify=FAIL, cipher=AES256-SHA, bits=256/256