Thanks for that.
I had gone through that early, but was not clear about the example given on that site. Below is the example from that site.
"For example all mail coming from network 192.168
route to mail.myisp.com and all email for nixcraft.com
It says for nexcarft.com
, but it is still not clear that mail routing will be done for FROM or TO domain. My understanding is for means TO domain will be considered.
i.e:- from firstname.lastname@example.org
from the above for will be newdomain.com
Someone please correct me.