iii) Get rid of the second MX.
A second MX doesn't get you anything unless your primary has been down
for at least 24 hours, and if that happens you'll have other things to
You sure ? I have a courier box doing secondary MX for our main
sendmail based server and I see a fairly constant stream of
mail destined for users on that sendmail server _all_ the time.
I thought a 2nd MX would get used as soon as the primary was
unavailable so I don't see how iii) can be a viable option.
My experience is that a secondary MX is used based on the connectivity
from receiving MTA. Not all routes on the Internet are equal.