Thank you! Appreciate the insight.

Crossing out the street address is an interesting thought. Although in the cases when it actually changes the zip code as well when it adds a street address... But I agree with you, USPS should be smart enough, especially when delivering to a giant IRS campus.

Regarding certified vs Priority, in most cases Certified + First Class actually ends up being close to half the price of Priority depending on what we are sending. I absolutely agree Certified does not provide the assurance that one expects it to, but truth be told we are mainly using it over Priority for cost purposes. We have had items returned to us when attempting to send large envelopes via First Class with tracking if the envelope isn't 3/4" thick. The reasoning on the "RTS" points to the thickness issue & states to use Priority or Certified when tracking is desired on envelopes. But, with Stamps.com, the 941-X's for ERCs I sent yesterday were $6.81 with Certified + Electronic Return Receipt. They would have been about $8 if sent Priority. Splitting hairs, but it ends up being a cost-effective option, and clients seem to like knowing their items were sent certified, if only due to the misconception you mentioned.