Distribution groups are the go-to solution for Outlook Web App users to communicate and collaborate with colleagues and partners. Manage distribution groups shows the distribution groups that you’re listed as an owner of. Use it to manage existing groups that you own.
Log in as yourself via OWA (https://outlook.office.com), select “Settings” (the gear icon) on the top right of the page then “View all Outlook settings” then “General” then “Distribution groups”
To edit a group or review information about a group:
Under distribution groups I own, Select the group you want to edit, then select “Edit” (the pencil icon)
Select on "membership" on the left of the new window.
To remove a member, select their name and select the Subtract icon.
To add a member, select the Add icon.
Select "message approval" on the left of the new window.
Select the checkbox next to “Messages sent to this group have to be approved by a moderator” to make all messages sent to the group require moderator approval.
To add moderators to the group, select the + sign, and select a moderator from the list that appears.
Senders who don’t require message approval:
To exempt some senders from moderator approval, select the + sign, and select an exempted sender from the list.
Choose when to send moderation notifications:
Notify all senders when their messages aren't approved.
Notify senders in your organization when their messages aren't approved.
Don't notify anyone when a message isn't approved.
Select “Delivery management” on the left of the new window.
By default, only people inside our organization can send to distribution groups in our organization’s address book. To restrict the senders inside organization who can send to the group, click the + sign, and select senders from the list that appears.