- Postal Bulletin 22645 - Contents Publications Publication 431 Revision: Changes to Post Office Box Service and Caller Service Fee Groups Effective March 21, 2024, Publication 431, Post Office Box Service..." /> - Postal Bulletin 22645 - Contents Publications Publication 431 Revision: Changes to Post Office Box Service and Caller Service Fee Groups Effective March 21, 2024, Publication 431, Post Office Box Service..." />