Plesk - Data Transfer Statistics SMTP IN and Out

Hi all

Just trying to understand the Data Transfer Statistics for Parallels Plesk Report, under the SMTP stats we have:

Total: 1918.40 MB
In: 1 887.07 MB
Out: 31.32 MB

What is Incoming SMTP traffic? Is that traffic sent to the SMTP server by mail clients? Does that include localhost SMTP transfers between the MTA and SpamAssasin?

Although I am familiar with servers I would rather have root access rather than a control panel but as I don’t my hands are tied to what the control panel says.

Thanks all

Matt Houldsworth