Currently, the system allows the creation of domain grouping based on the domain name, for example, for Google Network, gmail.com, or googlemail.com.
But most of us send mail to Google Workspace or Office365-based domains, which currently needs to be improved to create a group.
For example, one can do routing based on the following MX conditions.
Google Network:
Domain Name (match): gmail.com OR googlemail.com
MX (equal) (any):
Outlook Network:
Domain Name (match): outlook.com OR hotmail.com OR msn.com
MX (contains) (ends with): mail.protection.outlook.com
Proofpoint:
Mimecast:
MX (equal):
and there are many more like AWS, Zoho, Yahoo, Comcast, iCloud
The main reason behind this is to ensure better email routing. Some IP works well with Google Network and some don't or, some works fine with Office365 network but not with Google Network.
This way, the administrator can do proper routing and, which will increase better Inbox placement.