There are several legal ways to obtain these addresses. However,
please note that an answer on Google Answers is not an equivalent of
talking with a lawyer, which is what you should do, if you think you
need a legal advice here.
The first way, the easier way, is to purchase such a list from
companies that deal with marketing information. Some of these
companies can also directly mail the information to their subscribers.
Such lists are available from:
<http://nai.biz/nainew.php#dc37> - this one would probably best fit
Other sites that have golfers marketing lists:
<http://www.legendarymarketing.com/page/229-8421.htm> (this is a link
to their email list. However, they have many more marketing products).
See, for example:
"Golf Direct Mail Takes Swing at Co-Op"
The problem with these lists, including even the KMC list, that looks
"perfect" for your needs, is that the participants in these lists did
not express pervious interest in your product and that you are not the
owner of these lists.
Therefore, there is also a second way to get these email addresses, by
collecting them yourslef. This might be more difficult, but might get
you exact results, including elements that you might want to explore
like the name of the club.
On a web site - you can have a new website if you prefer not to
"expose" your marketing scheme at the beginning - you place an
incentive that would entice people to leave their details in a
quetionnaire form (from which you'll collect their email address).
What kind of incentive? A freebe or sweepstakes could be the answer.
If you promote your sweepstakes in places where golfers usually read
it (golfing sites, magazines, etc.) you will get your response.
Naturally, the second method to get addresses does not exclude the
first one and vice versa.
I hope this answers your question. Please contact me if you need any
clarification on this answer before you rate it.