ya, this is 2008, no one actually sends money in envelopes. whenever i get envelopes with plain cash, it's because they just hand it to me. whenever i get something in the mail, it's always a check
USPS - Insured Mail is what i found
Nvm i think this is it
USPS - Send Money
You have several options for adding security to the gifts and merchandise you send.
Security is key when you’re sending valuables through the mail. Whether you are sending jewelry, antiques or just expensive clothing, getting insurance provides that security. Insure your package only for what its contents are worth; you’re only covered for the actual value at the time and place of mailing.
Express Mail® automatically includes $100 of insurance coverage.
Fee . . . . . . . . . . Insurance Coverage
$1.65 ................ $0.01 to $50
$2.05 ................ $50.01 to $100
$2.45 ................ $100.01 to $200
$4.60 ................ $200.01 to $300
$5.50 ................ $300.01 to $400
$6.40 ................ $400.01 to $500
$7.30……………$500.01 to $600
$7.30 plus $0.90 per $100 or fraction thereof over $600 to $5,000.