light weight notification of received email
Currently to get notified of new email received you would need to use routes with either "forward" or "store" + "notify". Both these methods makes a request containing the full email body to the receiving service, since the body can be very large they can become up to 50MB in size.
I'm suggesting a new lightweight notification mechanism that would omit the email body and only contains necessary information for the receiving server to fetch the full email later asynchronously. This could be done by introducing a new "store" directive, "notify-light" or a similar name.
The benefit with this would be to reduce network used, the receiving server can make a decision if the email os of interest or not based on the meta data. Request retries would consume much less data since each request would be much smaller.