Note: Please do not make any of the changes listed below if you have backup MX records that point directly to your mail server and bypass Norman SecureMail. If you plan to remove your backup MX records, please allow at least 1 week for the DNS caches all over the web to clear before making the below changes.
We have found that spammers, as much as 20 percent, are intentionally delivering their spam to the lower priority MX and directing it to the customers’ servers thus bypassing Norman SecureMail. We highly advise using only the two MX records that Norman supplies. Norman’s servers should be the only servers sending inbound mail to your server. You will need to continue to allow all Outbound SMTP connections since the outbound mail leaves directly from your server and not through Norman SecureMail.
Only allow Norman SecureMail to deliver messages to your server.
Norman SecureMail Server Networks to allow on your mailserver/firewall for inbound SMTP:
18.104.22.168/25 – or 22.214.171.124 (addresses 129-254) with subnet mask of 255.255.255.128
126.96.36.199/26 or 188.8.131.52 with subnet mask 255.255.255.192
Norman SecureMail Server IPs to allow on your mailserver/firewall for inbound SMTP:
184.108.40.206 – Delivery server
220.127.116.11 – Alerts/Failover server
18.104.22.168 – Alerts/Failover server
22.214.171.124 – Alerts/Failover server
126.96.36.199 – Alerts/Failover server
188.8.131.52 – Alerts/Failover server
184.108.40.206 – Alerts/Failover server
220.127.116.11 – Custom TLS requirements delivery server
If you do not have a firewall, most mail server platforms have ways of limiting which IP addresses have permission to connect to your server’s SMTP service. Norman advises that the traffic be limited from your firewall. If you cannot do this, you may use the examples below to limit it from your mail server. Do not forget to include your firewall or other external devices that connect to you server.
Click here to view the Limit SMTP Exchange 2000 - 2003 tutorial video. This video will guide you through a step-by-step procedure on how to configure Exchange 2000/2003 and limit Simple Mail Transfer Protocol (SMTP). Once you view the video, you are ready to configure your Exchange 2000/2003 mail server.
Click here to view the Limit SMTP Exchange 2007 - 2010 tutorial video. This video will guide you through a step-by-step procedure on how to configure Exchange 2007/2010 and limit Simple Mail Transfer Protocol (SMTP). Once you view the video, you are ready to configure your Exchange 2007/2010 mail server.