# naglowki:

LDAPROOT=user=cn=exim,dc=firma,dc=pl pass=dupa.8 ldap://ldap.firma.com/ou=People,dc=firma,dc=pl

# (...)

begin routers:

lokalny_user:
  driver = accept
  domains = firma.com
  condition = ${if eq{${lookup ldapm{LDAPROOT?mail?sub?(&(objectClass=inetOrgPerson)(mail=${local_part}@${domain}))}}}{}{no}{yes}}
  transport = local_delivery

nielokalny_user:
  driver = accept
  transport = remote_smtp

# (...)

begin transports:

local_delivery:
  driver = appendfile
  maildir_format
  delivery_date_add
  envelope_to_add
  return_path_add
  directory=${lookup ldapm{LDAPROOT?uid?sub?(&(objectClass=inetOrgPerson)(mail=${local_part}@${domain}))}}