I am working on an issue with messagelabs in which they are suggesting that we hardcode messages destined for xyz.com to a name.of.cluster where both are names. I guess I'm asking how can I force GWIA to use an MX record I create instead of public DNS mx. Messagelabs says that we are randomly using a pref 20 mail exchanger which is causing issues with delayed messages until we resend to pref 10 mail exhchanger. The idea is that we tell gwia only to go to pref 10 mx.

Thanks in advance!