Is the mailbox that I buy and install on my porch (not the kind at the
end of the driveway) my property, or Federal property. Part two: If I
put something that is non-mail (say a loaf of bread) in the mailbox
for someone else to pick up, does the mailman have a right to take it?

Hi there!

According to Title 18, United States Code, Section 1705, residential
mailboxes are indeed considered Federal Property and are protected
under that same code against acts of mail theft, vandalism and
rifling:

United States Code TITLE 18  > PART I  > CHAPTER 83
http://makeashorterlink.com/?K10125B84

Tampering with mailboxes in any fashion is a felony offense:

"Mailboxes are considered federal property, and federal law makes it a
crime to vandalize them (and to injure, deface or destroy any mail
deposited in them)."

Tips to prevent mail theft, by Jim Walters, Woodinville Postmaster
http://www.nwnews.com/editions/2003/20030203/local19.html

...and mailboxes may be used *only* for mail:

"A mailbox becomes Federal property, she points out, the minute it is
in place and used. That assures the box can be used only for mail and
nothing else."

More, not all, of town will get postal delivery
http://www.s-t.com/daily/06-98/06-15-98/c03ad104.htm

"1.3Use for Mail

Except under 2.11, the receptacles described in 1.1 may be used only
for matter bearing postage. Other than as permitted by 2.10 or 2.11,
no part of a mail receptacle may be used to deliver any matter not
bearing postage, including items or matter placed upon, supported by,
attached to, hung from, or inserted into a mail receptacle. Any
mailable matter not bearing postage and found as described above is
subject to the same postage as would be paid if it were carried by
mail."

Domestic Mail Manual -  D041 Customer Mail Receptacles
http://pe.usps.gov/text/dmm/d041.htm#Rbi31049

As it happens, one of my neighbors is a US Postal carrier.  Kimberly
Al'Farrah states:

"Mailboxes *may not* be uses for anything other than proper mail.  If
it doesn't have postage, it does not belong in the mailbox.  Mail
carriers *may* remove *any* item in a mailbox that is not proper mail.

Your client may not put a loaf of bread or anything else in his
mailbox for someone else to pick up.  If he persists, he could be
charged with obstruction of mail, since a non-mail article could
prevent the carrier from delivering the mail."

Ooof.

Here's what one can expect if one is charged with obstruction of mail:

"Whoever knowingly and willfully obstructs or retards the passage of
the mail, or any carrier or conveyance carrying the mail, shall be
fined under this title or imprisoned not more than six months, or
both."

Sec. 1701. - Obstruction of mails generally
http://www4.law.cornell.edu/uscode/18/1701.html

Hope this helps!

--Missy

Search terms:  [ "federal property" mailbox ]...and I ran upstairs to
talk to my neighbor.

Missy: I will be sending payment from Federal Prison, I guess!! It is
a moody mailman indeed who removes a loaf of bread and abscounds with
it, federal laws notwithstanding. Tell your neighbor thanks, and thank
you for your speedy and interesting, if unwanted, answer. If I had put
a Pit Bull in the mailbox, or a rattlesnake, I could understand, but a
loaf of bread???? (Mailman took it.)

Thank you, groendog!

Perhaps a bit of mailman bribery might help?  Leave him a ham sandwich
and note to leave the loaf of bread alone?  Good luck!

--Missy