Roger Burns recently wrote:
>
>But there are two sides to this issue.  Protection also *attracts*
>subscribers.
>
 
I agree with this, but only from experience. A priori I would have agreed
with the earlier poster, who argued that too many layers of protection
are inhibitory.
 
As long as subscribers don't find it awkward to post and obtain regular
list mail,  many seem to prefer making accessing other features
a bit awkward at the margins in exchange from protection from spammers.
Every list is different; and some are expressly targeted more often than
others.  In the case of BIOSPH-L, I had the usenet gateway closed and set
posting to subscriber-only because of the prevalance of mail header
forging
in spam.  Since there is no way to get back at these spammers (and
attempts
to do so usually end up torturing innocent postmasters), I closed the
spigot for all but the most intent, and received support or at least
understanding from all the active participants on the list. Your list is
different, so your milage will vary.
 
Dave Phillips
BIOSPH-L list owner