[exim] Limit messages sent to smarthost per hour

Hi,

I would like to queue all messages to be delivered through a smarthost based upon some criteria, for instance the number of messages the smarthost can transport without blocking us for security reasons.

Some user in the domain sent thousand of mails in a short period of time and these mails bounced back by the smarthost with the following message:

   Domain xxxxxxxx has exceeded the max emails per hour (200/200 (100%)) allowed. Message discarded.

The desired behavior is not having bounces and discarded messages but queueing all messages just before reaching the maximum allowed by the smarthost, and releasing after a while. When queueing messages, some warning to the sender would be better.

The smarthost I'm using runs exim4, so the action on the counterpart (client side) should be possible to implement also on exim4.

Any help pointing me to the right direction?

Thanks in advance.


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Emilio Augusto Lazo Zaia