If you need to check various settings related to DNS records, I suggest you to use a free service – digwebinterface.com .
For example, you need to ensure you have set everything up for Google Apps on your domain (MX records). Here is how it should look like:
If you would like to check your nameserver records, just select NS in the list.
This great service allows you to check any kind of DNS records you might need. Highly recommended to those who need to set up/transfer sites to ensure everything is set up as needed.
