I know a shareholder of record list exists but not sure how physical addresses would be listed. I believe I am on that list as having originally started with a full service broker.
Don't know how they do it anyhow but Ive been with Ameritrade for a long time now And yahoo sent me share holder package also Alcoa and other companies Don't know how they Got my address and name but they do get them from somewhere. The hp one comes in a very nice package and nice paper too.
I believe the letter will go to the brokers and then they will distribute it to their people. To me, this is not a good way because not everyone will get it on the same day. A 'letter to shareholders' in the form of a PR would be better. All in my opinion.