Author: Dean Brooks Date: To: exim-users Subject: Re: [Exim] acl_not_smtp
On Mon, May 10, 2004 at 11:59:18PM +0100, Jeremy Harris wrote:
> OK, wishlist. The current situation seems to leave me with great
> difficulty in validating recipients, so I'm likely to be stuck
> with a long queue-residence followed by generating a bounce.
> I'd prefer to give instant feedback to a mis-typing MUA user.
> This seems to require verify=recipient, so I'd like an ACL which
> is run per-recipient for non-SMTP sourced mail, with
> local_parts and domains set as needed. I'd be happy if the rcpt_acl
> was coopted for the task.
The problem, as Philip noted, is that a non-SMTP message can
have multiple, even hundreds, of recipients in a single message.
Since the recipient list is not available until the message is
already received, there is no way to identify to the MUA which
user is invalid. Imagine 200 recipients, with only 1 that fails
verification. How would it report this to the MUA?
Also, keep in mind that most MUA's do NOT handle error codes from
/usr/lib/sendmail gracefully. They usually only understand "accepted"
and "error".
Generating a bounce is, IMO, almost always the best behavior for MUA
submissions, since Outlook and most other MUAs do not handle submission
level errors very well.
