in tab dns-manager of ispconfig2 I have added 7 MX record of google. but when I check with http://www.checkdns.net it has shown: Domain examble.com.vn has no MX records, but it has A record for domain. This configuration is not recommended so I can't use google apps mail. this main problem is it can't see any MX record although i have added. pls help me to solve this.
Wait some time. It takes up to 48 hours until new settings in dns get propagated. If you want to test your domain right now, do it on the commandline of the server and not with an external tool. run: dig @localhost MX yourdomain.com