[exim] Exim as an external filter : how to check recipient a…

Hi,

I want my Exim platform to act as an external filtering solution, mailboxes
being hosted on a remote server. That is,at the ACL level on receiving the RCPT
TO email address, to have it validate this very address against the remote
destination server.

I plan to do it that way: at the RCPT TO ACL level, if the recipient address
does not exist in my local recipient table, call an external Perl script which
would perform the checking (or have it run as a daemon and talk to it from Exim
via a UNIX socket), and depending on the result, accept the email address (and
add it to my local table) or return a 'user unknown' message.

Does that sound good to you ?

Thanks in advance for your help.

Christian