From USPS News Link:
Homeless individuals may not have a permanent residence, but they can still receive mail.
USPS offers general delivery mail services to customers with no fixed address and no identification.
According to USPS policies, there is no time limit for how long an individual may receive general delivery mail at a Post Office. Although mail is typically held for no more than 30 days, customers may request an exception.
The Postal Service works with the federal Interagency Council on Homelessness, which strives to end homelessness.
Consumer Advocate Consumer Advocate and Customer Relations Manager John Budzynski represents USPS on the council and helps resolve problems with delivery to homeless customers.