I used to send a beer-of-the-month box full of either homebrew or local commercial brews in exchange for friends' and relatives' local beers, but they were all so lethargic about returning it I eventually stopped.
Shipping from a commercial location by UPS or FedEx is fine, but they may not like it if you declare alcohol when dropping it off at the shipper's (UPS, FedEx) office. In other words, do all the shipping paperwork on-line and then simply drop it off at any commercial pick-up spot, like an office supply store.
It is illegal to use the postal service to mail alcohol, but not illegal to mail malt extract or yeast samples.