Double FYI, the USPS does sell personal data when you do a change-of-address:
https://www.forbes.com/sites/adamtanner/2013/07/08/how-the-p...
https://www.forbes.com/sites/adamtanner/2013/07/08/how-the-p...
I personally don't fill out the change of address forms.
Edit: Note, this is a "nice assurance to have" because private shipping companies generally reserve the right to open anything that they are shipping.
And again, with private shipping companies, it's not like they are going to open 100% of everything. But the large email companies can, and have it forever. Can look at it 10 years from now, if they choose.