From Essential Hacks (http://www.simania.nl/sdls/eh/sdls-eh.htm):

Buyable enhanced mailbox

For accidental deletions (use move_objects cheat to place outside lot boundaries)
or a safe way to up needs/relationships. The extra menu items (only in English and 
Dutch) will appear for both the standard mailbox on the lot and any new ones bought. 
(There can be any number of mailboxes on the premises and Sims can even collect mail 
from them, but mail is delivered to one mailbox only.) The job listing option (Deluxe 
upwards) works with the computer and the newspaper; order a new paper to see the new 
job offer. The "make me know people" and "friends" options will set relationships to 
neighbours at respectively 25 or 50 points; long-term relationships are not affected.
This mailbox will add bill amounts to your budget, instead of subtracting them.
The budget still has to be high enough to "pay" them, though, as the budget check 
is in a different object.
File: GameData\Objects\Mailbox.iff
Last uploaded: 03-01-2005
Catalogue: Outside, Misc, Misc.
Version: Livin' Large, House Party