Community
SOCIETIES
These societies might be of interest for zeppelin mail collectors.
societies
Zeppelin mail collectors clubs
There are not many zeppelin mail collectors clubs around, this is an overview over the few active societies:
THE ZEPPELIN COLLECTORS CLUB is a study unit of the American Airmail Society AAMS and affiliate #135 of the American Philatelic Society (APS).
http://www.ezep.de/zc/zc.html 
The largest international zeppelin study group, founded by John Duggan in 1987. You are currently on our website
http://www.ezep.de/zsg/zsg.html 
societies
Other societies with frequent zeppelin mail activities
These societies do not specialize in zeppelin mail, but they have frequent zeppelin mail activities:
Since Jim Graue took over editorship of the GPS publication, this society became quite heavy on zeppelin mail and catapult mail.
http://germanyphilatelicsocietyusa.org/index.html 
Their journal 'Air Mail News' has frequently articles on zeppelins
http://www.britishairmailsociety.co.uk/ 
Bob Wilcsek publishes there frequently zeppelin mail columns
http://www.americanairmailsociety.org/ 
societies
Other philatelic societies
It is not all about zeppelin mail: There are many other philatelic societies with a close relationship to the ZEPPELIN STUDY GROUP:
The center of German philately in the UK
http://www.germanphilately.org/ 
The source of philately and postal history of Hong Kong
http://www.hongkongstudycircle.com/ 