Re: [exim] Allowing sender verify when sender over quota

Jethro R Binks wrote:
> On Mon, 13 Aug 2007, John Horne wrote:

(snip)

> If a server returns any 5xx return code, it is saying "this is a permanent
> failure, I do not want you to try and deliver a message here to that
> address". Any more is purely informational.
>
> Since the point of sender verification (whether by absolute address using
> a callout, or testing deliverability to sender domain via MX checks) is to
> ensure you only accept messages to which a reply could be sent (to best
> effort), then what is the point of trying to work around this particular
> issue (probably on a case-by-case basis) by trying to parse the error more
> deeply than 5xx? Sender is over quota, therefore cannot receive reply
> messages, so why waste time accepting messages from them?
In addition, someone who is legitimately using their own email account is far
less likely to have a full mailbox than a mailbox whose email address was used
as the From address in a spam campaign. I would absolutely WANT to reject
messages that appear to come from an account whose mailbox is over quota,
simply for this fact. It's probably already full of bounces for spam that
this person may or may not have actually sent.