Any or all of the above.  Their agent's, mother inlaw's, etc.. USPS,
E-mail, Fax #, you name it. Got any ideas I haven't thought of?  I DO
NOT WANT TO INTRUDE INTO THEIR PERSONAL LIVES.  Difficulty scale 1 to
10, 10 most?  I am deaf and cannot phone.  I do not need money, I have
enough to live comfortably.
Regards,  Burt Rosenberg

Hello cimmyjagney,

I have found mailing addresses for all of the actors/actressses
mentioned above.  In all cases, there are multiple known addresses for
these people, I have listed all of the addresses I found below.

Jerry Seinfeld:
c/o CAA 
9830 Wilshire Blvd 
Beverly Hills, CA 90212
USA

147 El Camino Dr. #205 
Beverly Hills, CA 90212
USA

2971 Bellmore Ave., 
Bellmore, NY 11710 
USA

280 Elm St 
Southampton, NY 11968-3464
USA

9444 Sierra Mar Plaza 
Los Angeles, CA 90069
USA

211 Central Park W. 
New York, NY 10024
USA

Jason Alexander:
6230-A Wilshire Blvd. #103 
Los Angeles, CA 90048-5104
USA

355 N June St 
Los Angeles,CA 90020
USA

c/o WMA 
151 El Camino Dr. 
Beverly Hills, CA 90212
USA

c/o Daeson Entertainment 
10201 W. Pico Blvd Bldg 15 
Los Angeles, CA 90064
USA

103 South Harper Ave., SW 
Los Angeles, CA 90048
USA 9100 Wilshire Blvd #600 
Beverly Hills CA 90212
USA 

9100 Wilshire Blvd #600 
Beverly Hills CA 90212
USA

Michael Richards:
15322 Antioch St. #527 
Pacific Palisades, CA 90272-3628 
USA

12730 Halkirk St 
Studio City CA 91604
USA

c/o Castle Rock 
345 N. Maple Drive 
Beverly Hills, CA 90210
USA

242 Aderno Way 
Pacific Palisades, CA 90272
USA

c/o Creative Artists Agency 
9830 Wilshire Blvd 
Beverly Hills, CA 90212 
USA

Julia Louis-Dreyfus
c/o Creative Artist Agency 
9830 Wilshire Blvd. 
Beverly Hills, CA 90212 
USA

9150 Wilshire Blvd #205 
Beverly Hills, CA 90212 
USA

9911 W. Pico Blvd. #PH-1 
Los Angeles, CA 90035
USA

5757 Wilshire Blvd #1 
Los Angeles, CA 90036-3629
USA

c/o UTA 
9560 Wilshire Blvd. 5th Floor 
Beverly Hills, CA 90212
USA

535 Alma Real Drive 
Pacific Palisades, CA 90272
USA

Resources:
I found the information on the The Star Archive
website(http://www.stararchive.com).  It is free to lookup as many
star's addresses as you want.  They also have a feedback section where
users can comment on the accuracy of the reported addresses

Another resource is the See Stars address search page
(http://www.seeing-stars.com/Search.shtml).

Search Strategy:
mailing address celebrities

Good luck,
andyt-ga

Another resource

It is a great time saver and much more than I would have done on my own.