InPower Movement, October 30, 2017October 30, 2017, 0 Yes. See also: What do the Witnesses do at the Post Office? Do I need to use Zip/Postal Codes on the envelopes? Last Update: October 30, 2017 622 Mailing Your Documents Total 0 Votes: 0 0 Thank you. Please tell us how can we improve this post: Captcha: + = Verify Human or Spambot ? Related Knowledge Base Posts -Do I need to use Zip/Postal Codes on the envelopes?What is the recommended ordering of pages/documents in my mailing?What Post Office supplies do I need to pick up?