Correct MX records to use for Google Apps?
Solution 1:
As stated by google support the following settings should be used (or, they are recommended). aspmx.l.google.com is the main server and should have top priority (1).
Priority Mail Server
1 ASPMX.L.GOOGLE.COM.
5 ALT1.ASPMX.L.GOOGLE.COM.
5 ALT2.ASPMX.L.GOOGLE.COM.
10 ALT3.ASPMX.L.GOOGLE.COM.
10 ALT4.ASPMX.L.GOOGLE.COM.
Source: https://support.google.com/a/answer/33915?hl=en