Milter-greylist

Hi 

I am working on nsupdate support in milter-greylist, so that an action
clause in an ACL can trigger a DNS update, which enables milter-greylist
to feed a DNSRBL based on ACL conditions.

That first part works fine, but I thought about handling expiration of
added DNS record. It seems there is no way to tell the DNS that an added
entry should expire. That would suggest milter-greylist sould manage it,
which leads to a lot of complexity. 

What people think about it? Is expiration actually useful, and how to
implement it?

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu@...