On Wed, Jan 03, 2018 at 02:42:58PM +0100, Matus UHLAR - fantomas wrote:
> On 02.01.18 19:59, stefan novak wrote:
> > We are using the reject_unverified_recipient in combination with smtp
> > transport-table to submit the E-mail back to the exchange Server.
> > With our dovecot backends we can use the dovecot quota service in
> > combination with the check_policy_service that Mails from full
> > Mailboxes get rejected. How can i achieve this with our exchange
> > backend? Now the Mails get bounced, which is not very nice :/
>
> does exchange use temporary rejection for over-quota accounts?
More precisely, the OP should report the complete (unmodified except
for the recipient address where it is fine to hide the localpart)
response from the exchange server for an over-quota mailbox, and a
second response for a non-existent mailbox.
It should be possible to configure the address verification transport
used with Exchange (with care) to treat these appropriately, while
ignoring most other failures:
http://www.postfix.org/postconf.5.html#smtp_delivery_status_filter
http://www.postfix.org/postconf.5.html#default_delivery_status_filter
The address-verification positive cache time would need to be
sufficiently short to detect most quota-violations promptly.
Inbound quota violations could be made less frequent by having a
separate (lower) hard limit for sending mail than for receving
mail. A user who exceeds the "send" hard limit would be unable to
send mail until disk-usage is reduced below the quota soft limit,
but would still be able to receive mail. Presumably users would
take prompt action to be able to send email, and would then avoid
having any inbound email bounced.
I don't know whether Exchange supports limits of this type.
--
Viktor.
