On Fri, 24 Aug 2007, Magnus Holmgren wrote:
> Recipient callout verification takes care of nonexisting users (if no better
> method is possible) as well as other errors that can be detected at RCPT
> time. Later errors will result in an NDR, but to completely eliminate them
> you will need to complete all deliveries, whether local or remote, before
> returning an OK status. That can take a long time and would require a rather
> fundamental redesign.
Indeed. Remember that "a long time" might be days... The "better method"
referred to might be a shared database, LDAP or otherwise.
--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book
