Hi
> You have to implement an additional state machine, which
> coexists in front of your MTA. For doing this you need a
> database (mysql for
> example) where you can store a triple of ip address, sender
> address and recipient address for incomming connections.
No.
You can implement this with exim and a database only.
Preferably a database with stored procedures.
If you use firebird for example, you can connect to it with exim directly
(ibase) and pass sender and recipient to a stored procedure. That decides
about temporary reject or accept and returns that to exim.
If you have a database that does not implement stored procedures (afaik such
as mysql), you need to have more logic in exim, but it is still possible.
Anyway, avoid having something "in front of exim", as you need to implement
smtp for that purpose, which is not that easy. But it is, what exim is
designed for, so let it do it's job.
