Does Walmart have a 3 month supply of medicines by mail?

Do not know.

Walmart Pharmacy Home Delivery offers a number of financial benefits to customers. If your insurance company participates in the program, you may be able to enjoy bonus savings opportunities through the Pharmacy Home Delivery service. All of our Pharmacy Home Delivery customers can save money on their prescriptions by ordering a 90-day supply of medication through the delivery program. This adds both convenience and savings to your purchase because you'll have a full three months' worth of medication on hand each time your delivery order arrives to your shipping address. Pricing applies to specific generic medications at specific dosages that are the most commonly prescribed for that particular drug. If you request a name brand drug rather than the generic version, you may not receive the 90-day supply cost savings.

I doubt it

I'm not sure I have to use CVS