Ever since cPanel 11, I am noticing the following message at the bottom of the Edit DNS Zone form for a domain in WHM:

Always accept mail locally even if the primary mx does not point to this server. (Domain owned by acctusername)
The check box is always checked by default and I just don't get what this means.

I have MX records pointing to MXLogic spam filtering and the emails actually hosted by an external service provider (not in /etc/localdomains at all). That makes it all the more confusing.

Should I uncheck this box or leave it as it is?

Thanks for any insight anyone could offer.