GroupByDomain is used to group all email addresses from the same domain under one checkbox in the confirmation window. This setting is useful if you have a subset of users who regularly send emails to a very large number of recipients.
GroupByDomain is disabled (set to False) by default.
To group email addresses by domain:
- From within Outlook, click File > Options > Add-ins > Add-in Options
- Select Edit settings then, under the Logic tab, click Advanced
- Locate GroupByDomain and click on False in the next column to change it to True
- Click Close Window