How big is the slot on a USPS collection (blue) box?

What happen if I put a pre-paid International package into a USPS mailbox instead of giving it to an employee?

• I tried Click and Ship (via usps.com online) and printed my postage from home using my printer. I dropped the package in a post office drop box last night. When I got home I noticed the instruction sheet said "International packages my NOT be placed in a USPS collection box. Please present to a retail associate in a U.S. Postal Service retail outlet, hand to your letter carrier at the time of mail delivery or schedule a pickup service online at www.usps.com/pickup." What can I expect to happen? Will my package be returned to me?

• Answer:

  I just had this issue myself. I took my chances and mailed it anyway. I checked the tracking number a few days later and it got scanned into the system, no problem. It might be a bit risky for high-value shipments - since no one is accounting for the package. I suppose there's a chance that a dishonest employee may know this and steal it. Though the post office really checks their people out, plus there are cameras everywhere in their back rooms. I mailed a package worth $149 (which was clearly stated on the Customs Form) and it got into the system okay. As for the package being accounted for: I noticed on the Priority Mail Customs Form there's a section where the date and time the package is received is recorded/written in. Usually the employee you hand the package to fills in this information and initials it.