Before cutting your mail flow over to Proofpoint, double-check the following:
- Under Account Management > Features in Proofpoint, the "Enable Outbound Relaying" box should be checked
- In your DNS zone, verify that each of your active domains contains the entry for Proofpoint in their SPF record
To make the switch, update each domain's MX records to the following two records depending on your region:
US Customers
Type: MX
Host/name: @
Value: mx1-us1.ppe-hosted.com
Priority: 0
Type: MX
Host/name: @
Value: mx2-us1.ppe-hosted.com
Priority: 1
EU Customers
Type: MX
Host/name: @
Value: mx1-eu1.ppe-hosted.com
Priority: 0
Type: MX
Host/name: @
Value: mx2-eu1.ppe-hosted.com
Priority: 1
After confirming that the new MX records are live, it is highly recommended to delete the old MX records from your DNS.