Using MailHop with Firewalls
If you are going to restrict access to your mail server based on hostnames or IP addresses of our MailHop servers, you will need to subscribe to the system-status mailing list, available on the mailing list management page. DynDNS will periodically change addresses where MailHop servers reside but will announce changes as they are made so that you can make changes to your filters/firewall.
MailHop Backup MX
If you are using MailHop Backup MX, you will need to allow mx2.mailhop.org. If your software does not support hostnames, use the following addresses:
- 204.13.249.71
- 204.13.249.72
- 204.13.249.73
- 204.13.249.74
- 208.78.69.71
- 208.78.69.72
- 208.78.69.73
- 208.78.69.74
MailHop Relay
You should allow mail from our two primary netblocks, 63.208.196.0/24, and 204.13.248.0/24.