is there any downside to setting the reporting multiplier to 1?

[Tomki]

disclosure: I don't think so; the default inflation of 3 may or may not be valid, but it doesn't actually represent what happens on the system.  Maybe it's good for internal marketing?  So I see this post is more of a recommendation than a question.

Since the value is set to 3 by default; this means that for most environments the Overview page's Incoming Mail graph has other categories crushed under blue bars for "IP reputation" - incorrectly: the multiplier reporting to inflate every rejected connection by that value.  The implication of this is more than just a boasting of rejections, but also minimizes how much actual traffic is dealt with in other categories.

The value is set via the CLI only: reportingconfig -> mailsetup -> multiplier

There is no implication to actual traffic or other logic on the system, with either the default of 3 or my preferred 1.

[Libin Varghese]

There should be no downsides, however the default value of 3 is for the below reason.

Since we don't know number of messages that can be received on the connection that is rejected, a default multiplier of 3 is considered for every rejected mail. You may receive 1 email on a connection or 100 (depending on what's configured in the mail flow policies), so the reported numbers may be high or low depending on the way you look at it.

The rejection based on reputation happens before any additional email details (sender/recipient/email content) are received from them, this also helps reduce a lot of overhead on the device.

Regards,

Libin