Unfortunately there are lots of registrars that don't allow you full access to your DNS settings. 1and1.com is one of these. If you host your site with 1and1.com and you want to add a TXT record to your domain for verification purposes or to set a SPF record whatever, you simply can't do it... unless...
If you have access to another DNS server that allows you to edit your DNS zone and add TXT records, you can set your 1and1 domain to use that DNS server. However, THEN you must edit the DNS zone on that server and have all of the A records point back to the IP address for you 1and1 account.
Here are the steps:
- Ping your site and write down the IP address
- Go to the 1and1 admin domain listing
- Select the row for your domain (should be the only one checked) and the click DNS->Edit DNS.
- Select My DNS Servers
- Enter the URLS for your other DNS server (Something like ns1.example.com and ns2.example.com
- Close and save and allow a few hours for this to update before testing it.
- In the mean time, go to your other DNS server and setup a new DNS zone for your domain. It needs to have at LEAST an a record pointing to the IP address you wrote down for step one. You probably also want setup a cname for your www subdomain. You also can setup your TXT record.
- After hitting save wait for a few hours and you should be done.
If you are a visual learner, here is a screen cast.