[Mimedefang] Undesired consequence of stream_by_recipient

[David F. Skoll]

On Mon, 5 Apr 2004, Jim Hatfield wrote:

> I didn't appreciate that stream_by_recipient causes mail
> to be accepted before the validity of the recipient addresses
> has been checked.

Actually, this is a milter issue.  There is no way for Sendmail to tell
a milter that a recipient address is invalid.  It could in theory inform
a milter of an invalid local recipient address, but that wasn't written
into the milter code.

You can fix this by adding a filter_recipient routine that checks if
an address is valid and returns ('REJECT', "User unknown") if it is not.
This doesn't really affect Sendmail, but MIMEDefang is smart enough not
to add a recipient that *it* rejects to @Recipients when it comes time
to do content filtering.

It's a hack.  But it works.

Regards,

David.