I have no idea, but my computer room guys is asking me if I want my 6 physical GW mail servers all on one rack, or split across 2 racks.

Each rack has dual power supplies. So I'm thinking, "how redundant do I need things ?"

Does this matter ?

I have the following config;

SVR1 (PrimaryDomain ... SecondaryMailDomain)
SVR2 (POA1) 700 online users.
SVR3 (POA2) 700 online users.
SVR4 (POA3) 700 online users.
SVR5 (GatewayDomain ... GWIA1 ... GWIA2)
SVR6 (nothing yet).