What is the "Mail" Room, and where exactly is the swimming pool...or bath?

[TitanicNerd]

First, what the heck is the "Mail Room" on the Orlop Deck? Is it mail storage? Because I thought the post office on G Deck stored the mail. Also, where the heck is the swimming pool? It shows it on F Deck and G Deck. Or is just because the pool is really deep? And is it swimming pool, or swimming bath? Is there even a difference?

 

[Robert T. Paige]

First, what the heck is the "Mail Room" on the Orlop Deck? Is it mail storage? Because I thought the post office on G Deck stored the mail. Also, where the heck is the swimming pool? It shows it on F Deck and G Deck. Or is just because the pool is really deep? And is it swimming pool, or swimming bath? Is there even a difference?

This is one for the experts, but I'll make some guesses.
Due to the large voume of mail, probably they stored the mail on one deck, sorted it on another, etc.
The English term used in those days was "Swimming Bath."
"Swimming Pool" was more of an American term. Same thing.
Top on one deck. Extended into another deck due to the depth,

 

[Kyle Naber]

Here's a link that shows where the Turkish Bath and Swimming Pool is:

 

[TimTurner]

The mail room was a two-story complex with a stairway and service elevator connecting them. First class passengers (I believe) could bring letters directly to the post office during the voyage.

The pool is only on F deck (as far as passengers are concerned), but it is set into the floor, so it penetrates down into G deck. The pool wasn't unusually deep, it's just if you have a pool in your back yard, it penetrates underground.