> From: Terry
> I thought I had a handle on what I was doing in
> rejecting mail to unknown users but a discussion on another list and
> subsequent googling made me question it.
>
> I have the following in acl_smtp_rcpt:
>
> require
> message = 550 5.1.1 Bad destination mailbox address
> verify = recipient
I advise without "message", then error messages will be more specific.
For incoming mail (to local domains) to nonexistent users
a router should generate message like "Unknown user",
it'll be what sending MTA sees. Please post your such router.
> I ran across an entry on the exim wiki on recipient verification.
> https://github.com/Exim/exim/wiki/Verification#recipient-verification
>
> Recipient Verification
> Drop at connect time if the Recipient doesn't exist.
> deny message = REJECTED - Recipient Verify Failed - User Not Found
> domains = +all_mail_handled_locally
> !verify = recipient/callout=2m,defer_ok,use_sender
Recipient callout for domains handled locally (for incoming mail)
makes no sense and is not performed, the "callout" is ignored.
"callout" in "verify=recipient" is for outging mail (to remote domains).