Yes on both counts. InmateAid postcards are pre-stamped and go out through USPS in a format that is already approved for prison and jail mail delivery.
The pre-stamped requirement that some facilities enforce exists because loose stamps have become another method for introducing drugs into facilities. A stamp that has been soaked in a liquid substance and dried can look completely normal while carrying a controlled substance that activates on contact. Facilities that require pre-stamped mail are closing that particular vulnerability by ensuring the postage is already applied rather than arriving as a separate adhesive item.
InmateAid's postcards meet that requirement. They go out pre-stamped, printed on approved stock, and mailed through USPS in a format that mailroom staff across jails and prisons around the country recognize. The envelopes carry InmateAid's logo, which correctional staff associate with legitimate, vetted mail that has not been tampered with.
If the facility where your boyfriend is housed has specific requirements around pre-stamped mail, InmateAid's postcard service is designed to satisfy exactly those requirements without you having to navigate the policy yourself. The format compliance is built into the product.
If you ever have a question about whether InmateAid's mail format meets a specific facility's requirements before placing an order, email aid@inmateaid.com with the facility name and the team can confirm before anything goes out.