The ability to send mail to people who are offline which they would be able to open when they get online. A notification will appear,if they have mail, if they join the game. The mailbox could also have the capacity to save notifications for tribe invites, marriage requests, and so on if a person is offline.

Hmm, I like this idea. /Support.

/support
I was gonna suggest this but u beat me :c

good idea, so if you want to tell someone something like:
"meet me in room 801 on whatever o clock"
But that person is offline, you can leave a message for them
/support

I actually though of this idea.
/Support

/support
I like this idea .o.

There is already a thread for this. I cannot find it though.