kilos
pls give your opinion on the following:
main connection = adsl
secondary failover = 3G
If my second MX pointed to a dyndns on the 3G but the 3G is only opened when the main connection fails would this cause big problems? or would the first MX always be used unless its unavailable?
I would suggest rather get your domain hosted by a ISP in a datacentre then you'll never have problems. If the ADSL goes down then the mail just get stored on the server. Until you get things up and running again.