DNS records added via the "DNS Manager" section in the Control panel take effect only when the domain name uses the DNS service of your hosting account.
In order to add a TXT record, you need to:
1. Log into your Control panel and navigate to the "DNS manager" section.
2. You can apply the changes globally for all domain names parked on the hosting account, or for a particular domain name only. Select the appropriate option from the "Show hostnames of:" drop-down menu.
3. At the bottom of the page you will see an "Add a new record" field. Select "TXT" from the "Type" drop-down menu.
4. In the "Subdomain" field type the name of the subdomain/host for which you want the TXT record to be valid. If you want to add the record for the main domain name, leave this field blank.
Type your TXT record in the "Text" field and hit the "Submit" button.
For adding SPF records, please check the "Adding SPF records" article.
For adding SRV records, please check the "Adding SRV records" article.