They are supposed to give you a second (final) notice after 5 days, and return it to the sender 10 days after that (or 15 days from the date of the first notice).

I was guessing about two weeks, so I agree with Diane...and IIRC she's a postal employee!

Why it's always a good idea to have your mail put on hold or have a neighbor pick it up for you while you're on vacation or away on business!  

My daughter has been pet sitting for past 10 days and the family failed to return last night as planned due to the Debby storm!  She's hauled in 3 huge packages left on the porch while they were gone!