This offer is mainly targeted to newer PayPal accounts with little to no transaction history. My account is eligible even though I didn't receive the email.
Save the offer by 6/29 (or first 300,000) and redeem by 7/31:
$5 off automatically applies to purchases of $10 or more made in USD.
May also be possible to combine with the Honey $5 PayPal offer: https://www.joinhoney.com/paypal-get5/