How to email a group in Gmail and Outlook: groups, distribution lists, and shared inboxes explained

"Email groups" in Gmail and Outlook is a term that covers at least three different things, and the right setup depends on which one you actually need. This is the guide that separates them.

The three types of email group

Before setting anything up, work out which type fits your use case:

1. Personal contact group - you want to send an email to a saved list of people without typing each address. Just you. Not shared.
2. Shared inbox / collaborative inbox - a mailbox (e.g. support@company.com) that multiple people can read and reply from. The group has an address; team members log in and manage it together.
3. Distribution list / mailing list - an address (e.g. marketing@company.com) that fans out to a set of recipients. Replies go back to the sender, not to the group.

Most searches for "Gmail groups" or "Outlook groups" land on articles about one type when the person wanted another. Read the three sections below and pick the right one.

Gmail: personal contact groups

Gmail doesn't have "groups" as a first-class concept inside the compose window. The feature lives in Google Contacts and is called a label.

1. Open contacts.google.com and create a new label (left sidebar → "Create label").
2. Add the contacts you want in the group to that label.
3. Back in Gmail, type the label name in the To field. Gmail will suggest it and expand it to all the addresses when you select it.

A few things worth knowing: the label is private to your Google account. If you want the same group to be available to your whole team, that's a different feature (see Google Groups below). Also, Gmail expands the group in the To field when you select it - which means recipients can see each other's addresses. If that's a problem (e.g. sending to a client list), put addresses in BCC instead.

Outlook: personal contact groups

Outlook calls this a Contact Group (older versions called it a Distribution List, which is now a different org-level thing - confusingly).

1. In the desktop app, go to People (the contacts icon) → New Contact Group.
2. Name the group, click "Add Members," and add addresses from your address book or type them in directly.
3. Save. In the compose window, type the group name in the To field and Outlook will resolve it to all members.

In Outlook on the web (the new Outlook / OWA), the path is People → New contact → New contact list. It works the same way. Like Gmail labels, this group is personal - it lives in your mailbox, not in the directory.

Shared inboxes

Gmail: Google Groups collaborative inbox

Google Groups can be configured as a collaborative inbox, which is the Gmail-ecosystem equivalent of a shared mailbox. The group has an email address (e.g. support@yourcompany.com). All members can see messages sent to that address, assign conversations, mark them resolved, and reply from the group address.

To set one up: go to groups.google.com → Create group → set the Group type to "Email list" or "Collaborative inbox." The collaborative inbox option adds conversation management features (assign to, mark resolved, lock) on top of standard group email. Requires Google Workspace - free Gmail accounts can create Groups but with fewer admin controls.

Outlook: shared mailboxes

In Microsoft 365, a shared mailbox is a dedicated mailbox (with its own email address) that multiple people can access. Team members add it as an additional account in Outlook and can send from it - the From address shows the mailbox address, not the individual's. Shared mailboxes are created in the Microsoft 365 admin centre; they don't require an extra licence for most scenarios (up to 50GB storage).

Don't confuse shared mailboxes with Microsoft 365 Groups (the ones that come with Teams, SharePoint, and a shared calendar). Both have a group email address. The difference: Microsoft 365 Groups are collaboration hubs (Teams, files, calendar all connected); shared mailboxes are just email.

Distribution lists and mailing lists

Gmail: Google Groups as a mailing list

This is the classic use case for Google Groups: an address like all-hands@yourcompany.com that delivers to every member. When someone emails the group address, all members get a copy. Replies go to the sender (or to the group, depending on settings).

Group owners control who can post (anyone on the internet, organisation members only, or owners only), who can join, and whether new member posts require moderation. For internal announcements: restrict posting to owners. For open discussion: allow all members to post.

Outlook: distribution lists vs Microsoft 365 Groups

In Microsoft 365 there are two org-level group types that both accept email:

Distribution lists are the simplest: an IT admin creates them in the Microsoft 365 admin centre (Groups → Add a group → Distribution). Members don't get a shared inbox - they just each receive a copy of messages sent to the list.

Which one should you use?

Common problems

Replies going to the wrong place

In Google Groups the "Reply to" setting controls whether replies go back to the group address (everyone sees the reply) or directly to the sender. Check this setting before going live - it's the most common source of confusion when groups behave unexpectedly. In Outlook, distribution list replies always go to the original sender by default; Microsoft 365 Group replies go to the group inbox.

External senders can't reach the group

Both Google Groups and Microsoft 365 distribution lists default to blocking external senders. If you need a group address reachable from outside your organisation (e.g. a sales@ address), check the group settings and explicitly allow external email.

Group members receiving duplicate emails

If someone is both a direct recipient (To/CC) and a member of a group also in the To/CC, they may get the email twice. Gmail suppresses this in some cases; Outlook/Exchange does not always. Avoid putting individuals in To/CC when you're already addressing the group.

When AI triage helps with group inboxes

Shared inboxes and Google Groups collaborative inboxes get messy fast when volume picks up. Messages arrive, sit unassigned, and multiple people either reply or nobody does. An AI triage layer that reads incoming messages, classifies intent, and drafts an initial reply - with a human approving before it sends - cuts the coordination overhead significantly. That's the model Inboxer is built on, and it applies equally to individual and shared inboxes.