Please add ALL of the delivery IP addresses to your firewall or filters. 

These are the IP's that we use to deliver mail to your servers and having an accurate list configured on your firewall or filtering tool will ensure that you your email arrives at it's destination. 

This list was updated and shortened on Friday, April 15, 2016 with European Servers

IP ADDRESSES FOR OUTBOUND SMTP SERVERS - these are not required for Gateway, Email Forwarding, MX Backup, Hosted Email Customers. 

Delivery Servers

These IP's need to be in your firewall to ensure delivery from our network to your email server. 

Delivery Group 1 North America Zone 1

Delivery Group 2 North America Zone 2

Delivery Group 3 - North America Zone 3

Delivery Group 4 -  European Union Zone 1