The American rights to the product were once held by R. J. Reynolds (I didn’t know they had any food interests, they merged with Nabisco at one point)
It’s been many many years since I’ve their commercials on tv. I haven’t looked for it in stores. Maybe yuppie stores have it. Walmart is selling online and says they have it in some stores.
http://www.walmart.com/ip/Grey-Poupon-Dijon-Mustard-8-oz/10309003.
Check your email. :)