Mail360 Server (version 2.1) Is there a way to prevent Mailer IDs (MIDs) from being automatically added to the Server's DB?

The Mail360 Server User's Guide says-
Automatic Handling of New Mailer IDs
MAIL360 Server automatically adds new, or unfamiliar, mailer IDs when they are encountered during processing. These are assigned a default numbering scheme, allowing users to create and submit jobs with little required preprocessing.

There are options in the Mail360 Server's User Interface to control what number scheme will be used to add new MIDs into, but there is no option to prevent them from being added. 
Environment Details

UPDATED:  March 31, 2017