Milter-greylist

hello,

i am sorry, it was my mistake, it turns out that we have
misconfigured seconday MX severs that uses rockliffe mailsite
(windows). i didn't notice this misconfiguration before 
because we never actually needed the secondary MX.

now it works fine, but i have to whitelist my secondary
MX (addr), so hotmail messages always pass thru.

however, i still wonder why hotmail always tried the secondary
MX server and yahoo didn't.

if i do not whitelist my secondary MX server will milter-greylist
recognise the message is coming from hotmail rather than from
my secondary MX?

javier