Methods for domain verification for Google Apps

You must verify your domain before you can use Gmail or any of your other new services.

1. Create a TXT record - Up to 48 hours
2. Upload an HTML file - An hour
3. Add a <meta> tag to your home page - An hour
4. Verify using your Google Analytics tracking code - within 24 hours

If you signed up for Google Apps, you must verify domain ownership within 14 days. For Google Apps for Business or Education, you have 21 days. If you don't verify ownership within this timeframe, we'll remove your domain and data from our system. If you want to use Google Apps in the future, just sign your domain up, again. Google Apps for Business, you can contact our Support team for help with other verification or setup tasks.

See this link for more information