2 Windows domain? how to connect 2 servers?

Hi for first- sorry me for my bad english))

I am hawe 2 windows domains exempl: mamba.com end heramba.com? i am hawe 2 openfore servers im.mamba.com end im.heramba.com

all penfire servers ar in one ip subnet end can connect ower tcp/ip, securiti permisions can complite.

how i am can connect 2 servers ? mamba server hawe shared contact list “1” end heramba server hawe contact list “2” how users of mamba server can see heramba contacts ? OR ONE OPENFIRE Server can hawe 2 Active direstory connections end hawe 2 domains ?

PLS help me.