Hosted Email Add the following records to your DNS settings.
(Note that your DNS settings are not at Duocircle, they are with your DNS provider.)
example.com MX 10 mx1.mailhostingservice.com (10 is the priority and must be entered.)
mail.example.com CNAME mail1.mailhostingservice.com
webmail.example.com CNAME www.mailhostingservice.com
Backup Email Add the following record to your DNS settings.
example.com MX 20 mx1.mailhostingservice.com (20 is the priority and must be a higher number than the primary service MX.)
Front-end Email service and Forwarding Email service add the following record to your DNS settings.
example.com MX 5 mx1.mailhostingservice.com (5 is the priority and must be entered.)
The TTL on all these records should be around 1 hour unless you are making changes in the near future.
Note: you should replace "example" with your domain name