The mailing list for listmasters using Sympa

[<address@concealed>]

Hello,
 i'm trying to use sympa as a listserv replacement for our archive.
I wished that the list was completely public readable but with email address
protected in some way. I tryied the   AT   feature and seems to work, my next
step is trying to understand how to set correct permissions on the "arc" 
folder
so that nobody can simply bypass and read address such as
http://www.mysite.com/sympa/mylist/2007-05/arctxt/1  or
http://www.mysite.com/sympa/mylist/.mhonarc.db

which contains all email address in clear text

thanks,
alessio