Plan for governance in Office 365 Groups

Distribution Lists & Microsoft 365 Groups

Microsoft 365 gives you several ways to group people together for communication and collaboration. This guide explains the differences between group types and walks through creating and managing each one from the Microsoft 365 admin centre at admin.microsoft.com.

Which Group Type Should You Use?

Distribution Lists

A distribution list is an email address that, when sent to, delivers the message to every member. Members cannot reply to the group — it is one-way delivery only.

Create a distribution list

1. Go to admin.microsoft.com → Teams & groups → Active teams & groups.
2. Click Add a group.
3. Select Distribution list and click Next.
4. Enter a Name and optional Description. Click Next.
5. Enter the group's email address (e.g. allstaff@yourdomain.co.uk). Click Next.
6. Review the settings and click Create group.

Add members to a distribution list

1. From Active teams & groups, click the distribution list name.
2. Click the Members tab → View all and manage members.
3. Click Add members, search for users and click Add. Click Save.

Allow external senders to email the distribution list

By default, only people inside your organisation can email a distribution list. To allow external senders:

1. Click the distribution list → Settings tab.
2. Under External senders, tick Allow senders outside my organisation.
3. Click Save changes.

Mail-Enabled Security Groups

A mail-enabled security group works like a distribution list but can also be used to control access to files, SharePoint sites, and other resources. Use this when you need both emailing capability and permission control.

Create a mail-enabled security group

1. Go to Teams & groups → Active teams & groups.
2. Click Add a group → select Mail-enabled security → Next.
3. Enter a name, description, and email address.
4. Click Create group.
5. Add members as described above.

Microsoft 365 Groups

A Microsoft 365 Group is a collaboration workspace. Every group gets a shared inbox, shared calendar, SharePoint document library, and optionally a Teams channel. Use this when a team needs to work together — not just receive email.

Create a Microsoft 365 Group

1. Go to Teams & groups → Active teams & groups.
2. Click Add a group → select Microsoft 365 → Next.
3. Enter a Name and optional description. Click Next.
4. Assign one or more Owners — these are the people who can manage the group membership. Click Next.
5. Enter the group's email address and choose the Privacy setting:
   • Private — only approved members can join (recommended for most teams)
   • Public — anyone in the organisation can join
6. Click Next, review settings, and click Create group.

Add or remove members

1. Click the group name → Members tab.
2. Click View all and manage members.
3. To add: click Add members, search, and select.
4. To remove: hover over the member and click the X next to their name.
5. Click Save.

Allow people outside the organisation to join

1. Click the group → Settings tab.
2. Under Allow people outside my organisation to send emails to this group, toggle this on.
3. Click Save changes.

Managing Group Owners

Owners can add or remove members, change the group name and description, and delete the group. You should have at least two owners per group to avoid an unmanaged group if one owner leaves.

1. Click the group → Members tab → View all and manage owners.
2. Click Add owners, search for the user, and click Add.
3. Click Save.

Deleting a Group or Distribution List

1. Go to Active teams & groups.
2. Tick the checkbox next to the group.
3. Click Delete group in the toolbar.
4. Confirm the deletion.

Warning: Deleting a Microsoft 365 Group also deletes its shared inbox, calendar, SharePoint site, and any Teams channels. This action can be reversed within 30 days by restoring from Deleted groups.

Naming Policy for Groups (Admins)

If you want to enforce a consistent naming convention for groups (e.g. all groups must start with a department code), you can set a naming policy:

1. Go to Settings → Org settings → Microsoft 365 Groups.
2. Under Group naming policy, set a prefix or suffix.
3. Click Save.

Admins creating groups via the admin centre can bypass the naming policy — it applies to users creating groups from Outlook, Teams, or SharePoint.

Troubleshooting

Emails sent to the distribution list are not being delivered

• Check that the sender is allowed to email the group. By default, only internal senders can. Enable external senders if required (see above).
• Verify the group's email address is correct — check for typos in the group settings.
• If a member is not receiving emails, confirm they are still an active member of the group.

Cannot find the group in Outlook's address book

• New groups can take up to 1 hour to appear in the Global Address List (GAL).
• Confirm the group is set to appear in the address book: click the group in the admin centre → Settings → ensure Hide this group from the global address list is not ticked.

Microsoft 365 Group emails are going to individual inboxes rather than the shared inbox

• By default, members receive group emails in their own inbox. To change this, each member should go to Outlook → right-click the group → Group settings → untick Send all group email and events to members' inboxes.

A group was accidentally deleted

• Go to Teams & groups → Deleted groups.
• Select the group and click Restore group.
• This is only possible within 30 days of deletion.

Related Guides

• Groups naming policy
• Office 365 Group Expiration Policy
• Manage creation of Groups
• Basic mailbox settings for Outlook and other email clients (POP/IMAP)
• Share calendars with external users

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