retrieving deleted emails

[tere12]

I get my .mac email in my Eris.
When I delete my mac.com email on my Eris,
it does not go to the trash folder in
my Mail application on my Mac. (It also does not
go to the Trash folder in my cell phone)
It completely disappears.

I have my mac email Preference settings set to never delete mail from Server,
and also, to SAVE deleted email in my Server.

How do I retrieve deleted email from my Server?
thanks!