After the 2.1 TBC “Black Temple” release, followed 2.1.3, a mini-patch which changed both mail retention and mail sending times:
- Read in-game mail will now be kept for thirty days instead of three.
- Any mail between characters on the same account is now instant regardless of money or items attached.
- Any mail sent from a character on a different account will now have a one hour delay regardless of money or items attached.