General System Information
Client Mail Server
Device Network Configuration Nameservers
At least two of:
When you register a domain name, add these into the DNS records:
Spam Experts Mail Delivery
If you only want to accept mail delivery from our spam / virus protection provider, you must allow delivery from this host:
Our provider uses multiple IPs in multiple data centers for redundancy (and DDOS protection) so there is no static list of IP addresses. Most firewalls and MTAs will allow for this and there is a helpful Knowledgebase article that explains how to do this for several types of software.