In order to add your SPF record please login to the hosting control panel and go to the Manage DNS section.
Towards the bottom of the Manage DNS page you will see 3 inputs to allow you to add new records:
[list]
[*]Leave the "Name" field blank
[*]Select "TXT" for Type
[*]Enter "v=spf1 include:spf.stackmail.com a mx -all" as data.
[/list]
Once the changes are saved the domain is now protected by an SPF record. You can use the same record for all domains that use our mail services, however it should be noted that the above record will tell external providers all of your e-mail should originate from our network. If this isn't the case the record should be updated accordingly.