In order to add 123-reg MX records for your domain name so that 123-reg email works, please do the following:
2
In the Domain names section, select the relevant domain name in the drop-down list and click on the Manage button.
3
Scroll down to the Advanced Domain Settings section and click on the Manage DNS (A, MX, CNAME, TXT) link.
4
From the Basic DNS tab.
5
Click on the Change button in the EMAIL SETTINGS (MX RECORDS) section.
6
Select 123-reg email from the Your email is pointing to: drop down list.
7
Click on the Point to service button.
8
Click on the Confirm button to complete the change.
Please Note: It will take between 24 - 48 hours for the new MX records to become active.