Learn how to restrict traffic to your mail servers so that inbound email does not bypass Symantec Email Security.cloud.
To ensure that inbound (incoming) email does not bypass Email Security.cloud, you must implement a restriction to allow email traffic to and from Symantec.cloud-related IP ranges. This restriction helps prevent spammers from sending email directly to your server's IP address.
Note: Only traffic on port 25 needs to be "locked down" to and from Symantec.cloud IP addresses.
See IP ranges for Symantec.cloud.
Due to the diverse range of mail servers and firewalls in use, we cannot provide instructions or support for the configuration of IP address allow lists in firewalls or mail servers. Contact your IT department, IT consultant, or software vendor for assistance.
Caution: The suggested mail server or firewall configuration changes should be done only after full MX record propagation is complete. Allow 72 hours from the time your MX records have been changed for full propagation across the Internet.