92 Ill. Adm. Code 532.410
Postal Regulations
Section 532
Section 532.410 Postal
Regulations
a) Postal regulations require that a mailbox be located, whenever
possible so that the mail carrier's vehicle is off pavement when serving the
box.
b) Postal regulations require that mounting posts be neat, of
adequate strength and size, and that the bottom of the mailbox be 38 to 40
inches above street level. (See Illustration B and C)