Offer people an @postoffice.com government-grade secure email address, and they can get all their mail through there, including coupons, junk mail, catalogs, etc.
Offer a paid monthly subscription for those who want privacy and no pop-up ads.
The USPS should then completely abolish home mail delivery, partner with UPS and Fed Ex, and let people pick up their mail at a UPS Store or Fed Ex Office building. I had a UPS Store mailbox last summer, and it worked wonders when I travel.
For rural areas, the USPS could build secure buildings that houses post office boxes.
It's time that Congress let the USPS join the 21st and digitize. There is no need for physical regular mail delivered by overpaid union hacks in trucks anymore.
Also to add, the USPS could buy MoneyGram or Western Union, and offer online bill pay and get into the short-term lending business.