Milter-greylist

> If you choose LDAP you have to write your own LDAP schema adding milter
> greylist required fields. Then you have to write a GUI allowing LDAP
> users to modify the milter-greylist fields. You must define LDAP ACLs
> that allow that. It's probably a good solution for a big site having an
> LDAP server but it needs users to have a GUI.
> 
> 
> > 
> > Or are there other good ways of handling the issue?
> >
> The simple way to allow users to interact with some milter-greylist
> parameters is  a web interface (form/cgi or php) running on the mail
> server to add/delete their own ACL in a separate conf file (eg
> greyusracls.conf). You also have to authentify them and the best for
> that is to have an LDAP server .... So LDAP seems to be the right choice
> but it's heavy for admin and milter-greylist.

Having per-user conf file is an error prone architecture. In general,
file I/O is evil. In particular, milter-greylist need to parse conf
files of all users everytime just an user changes his/her preference.

For a LDAP-running site it will be easy to introduce a greylisting
preference in its existing LDAP database. For a SASL or UNIX passwd
site a monolithic file like /etc/passwd may be more attractive.