I did that for one of my amazon accounts a few years back when i registered at an amazon conference (probably aws reinvent)- i.e. amazon@mydomain.com - and for about 6 months I got onto some internal email list at amazon/aws, definitely not intended for the public, likely because someone queried for all email address that had 'amazon' in the address from this registration list - thought it was pretty funny, but eventually they stopped - someone probably figured out what they did wrong.
Also have one for thifty@mydomain.com (the car rental company) - when they saw my email address at the counter they gave me the employee discount rate - I didn't correct them :)