Having no response (not blaming anyone in this forum, but I was a bit in a hurry), I've eventually developed a custom call forward solution: a Perl daemon is responsible for checking email adresses' validity, and listens on a TCP port wich Exim uses to provide it with an email address and read back its status. The cache is in a MySQL table.
Christian -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
