To add an SPF record to your domain name, please do the following:
1
You will need to generate the record first this can be done at Microsoft's SPF record wizard
2
Once you have the record, you will need to apply it to your domain name, this is done in the 123-reg control panel.
3
In the Domain names section, select the relevant domain name in the drop-down list and click on the Manage button.
4
Scroll down to the Advanced Domain Settings section and click on the Manage DNS (A, MX, CNAME, TXT) link.
5
From the Advanced DNS tab.
6
Select TXT/SPF from the Type drop down list in the Add new entry section.
7
In the Hostname field enter an @ symbol.
8
In the Destination TXT/SPF field enter your SPF record.
9
Click on the Add new entry button to save the new record.