Pirate Ship is great if you want deep USPS discounts—up to 87% off—and...

https://shipping-discounts.s3.amazonaws.com/goshippo/video/pirateship-shipping-reviews.html

Pirate Ship is great if you want deep USPS discounts—up to 87% off—and straightforward, no-fee shipping. Just note, their support is email-only, and they don’t offer DHL Express. If you need more carrier options or faster help, Shippo might be better