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

On Mon, 13 Aug 2007, John Horne wrote:

> Running Exim 4.62, we use sender verification.

Using callouts? An admission which is rant-bait for some!

> However, it seems that if the original sender has exceeded their mailbox
> quota, then when Exim performs the sender verification it receives back
> a 552 code. Subsequently the message is rejected.
>
> Does anyone know if it is possible to allow sender verification to
> 'suceeed' rather than fail, even if the sender is over quota. To me it
> seems that the server has accepted the recipient, and, barring the quota
> limit, would have accepted the message.
>
> I have checked through the docs, and done some testing with the
> $acl_verify_message and $sender_verify_failure variables, but these do
> not seem to provide any detailed information about the verification
> failure. If they included the actual server response (something like
> '552 Quota exceeded') then we could of course look for that and act
> accordingly.

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?

Jethro.

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Jethro R Binks
Computing Officer, IT Services
University Of Strathclyde, Glasgow, UK