[exim] callback / sender verification

Hi all

Im trying something new in my ACL acl_check_rcpt, I basically added the following,

require verify = sender
         accept  domains = +local_domains
         endpass
  message = "The recipient cannot be verified.  Please check all recipients of this message to verify they are valid."
    verify = recipient

accept domains = +local_domains


Would someone be so kind as to proof read this, any tips / advise would great fully be appreciated.

Kind Regards
Brent Clark


==============================================================================
acl_check_rcpt:

# Accept if source is local SMTP (i.e. not over TCP/IP). We do this by testing for an empty sending host field.
accept hosts = :

   # Deny if the local part contains @ or % or / or | or !. These are rarely found in genuine local parts, but are often 
tried by people looking to circumvent relaying restrictions.
   deny    domains       = +local_domains
           local_parts   = ^[.] : ^.*[@%!/|]
           message       = restricted characters in address

   deny    domains       = !+local_domains
           local_parts   = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
           message       = restricted characters in address

   # Accept mail to postmaster in any local domain, regardless of the source, and without verifying the sender.
   accept local_parts = postmaster
          domains = +local_domains

   deny message = sender envelope address $sender_address is locally blacklisted here. If you think this is wrong, get 
in touch with postmaster
        !acl = acl_whitelist_local_deny
        senders = ${if exists{CONFDIR/local_sender_blacklist}\
                              {CONFDIR/local_sender_blacklist}\
                              {}}

   deny message = sender IP address $sender_host_address is locally blacklisted here. If you think this is wrong, get in 
touch with postmaster
        !acl = acl_whitelist_local_deny
        hosts = ${if exists{CONFDIR/local_host_blacklist}\
                              {CONFDIR/local_host_blacklist}\
                              {}}

    #sender verifications are required for all messages that are not sent to lists

         require verify = sender
         accept  domains = +local_domains
         endpass

         #recipient verifications are required for all messages that are not sent to the local machine this was done at 
multiple users requests

   message = "The recipient cannot be verified.  Please check all recipients of this message to verify they are valid."
    verify = recipient

accept domains = +local_domains

   accept domains = +local_domains
          endpass
          message = unknown user
          verify = recipient

   accept domains = +relay_to_domains
          endpass
          message = unrouteable address
          verify = recipient

accept hosts = +relay_from_hosts

accept authenticated = *

deny message = relay not permitted