Learn how to create a custom rule that prevents mixing up customer/client/vendor domain names.
A limit of 100 entries per group exists and the entries between groups have an 'AND' relationship.
For example, if you enter clientA.com in one group and clientB.com in a second group, a user sending an email to sam@clientA.com and sam@clientB.com would result in an alert for both recipients.
The grouping function can be used to organize entries based on client type, geographic location, or any other categorization method. If you need to enter more than 100 domain names without any particular grouping, simply use however many groups necessary to capture all required entries.