Using Google Mail

Step 1 : http://www.google.com/a/cpanel/domain/new

Step 2 : Create verification html file and upload to directory

Step 3 : Select domain, point to default IP then set the below

Priority    Mail Server
10    ASPMX.L.GOOGLE.COM.
20    ALT1.ASPMX.L.GOOGLE.COM.
30    ALT2.ASPMX.L.GOOGLE.COM.
40    ASPMX2.GOOGLEMAIL.COM.
50    ASPMX3.GOOGLEMAIL.COM.

OR

Priority    Mail Server
1       ASPMX.L.GOOGLE.COM.
5       ALT1.ASPMX.L.GOOGLE.COM.
5       ALT2.ASPMX.L.GOOGLE.COM.
10    ASPMX2.GOOGLEMAIL.COM.
10    ASPMX3.GOOGLEMAIL.COM.