Choose an alternative to catch-all after moving to Microsoft 365

A catch-all email is an account that collects messages addressed to a misspelled or a non-existent email address on your domain name. It could result in the delivery of unwanted mail, including spam. To prevent the risk of phishing attacks and other security threats, Microsoft 365 doesn't allow or support catch-all email.

If you used a catch-all with Workspace Email, it’ll no longer work after you move to Microsoft 365. You can choose from several of Microsoft 365’s existing features as an alternative (we strongly recommend this option) or continue to the rest of the article to set up an experience that simulates a catch-all email.

Use any of the following as a safer alternative to a catch-all email:

Alias: Create an address that sends all your mail to another inbox of your choosing. For example, if your address is jane@coolexample.com, and you create the alias sales@coolexample.com, all mail that’s sent to either jane@ or sales@ automatically goes to jane@coolexample.com. Create an alias.
Distribution group: Instead of contacting individual recipients, send one email to a group of people, such as a department or team working on a project. When you send mail to the distribution group, every member receives it. Create a distribution group.
Shared mailbox: Give a group of people the ability to read and send messages from a common email address. For example, you can set up the shared mailbox questions@coolexample.com so employees who have access can receive and respond to its messages. Create a shared mailbox.

Or, create an experience that simulates a catch-all email:

If your business needs catch-all email, an admin can create a similar experience where mail sent to any of your account's domains goes to a single mailbox. Please keep in mind that Microsoft doesn't support catch-all email and we recommend using one of the options above instead.

Step 1: Change the domain status

First, change the domain status so it accepts messages to recipients that don't already exist in your organization and aren't valid users.

Sign in to the Exchange admin center. Use your Microsoft 365 email address and password (your GoDaddy username and password won't work here).
In the menu on the leftmost side, select Mail flow, and then select Accepted domains.
Select your domain name. A menu will open on the rightmost side. If the menu doesn't open, make sure you selected the domain itself, and not the checkbox next to it.
On the rightmost side, select Internal relay.
Select Save. You'll see a success message when your domain's updated.
Required: If you have multiple domains in your Microsoft email plan, they're listed on the Accepted domains page. You must change every domain you want to work with the catch-all email to Internal Relay.

Step 2: Create a shared mailbox

Next, create a shared mailbox to check mail caught by the catch-all.

In the menu on the leftmost side, select Recipients, and then select Mailboxes.
Select + Add a shared mailbox.
Enter the following:

Display Name: This is what recipients will see when they get mail from this address.
Email address: Name the email address catchall before the @, and then select your domain from the list.

Select Create. You’ll see a success message when the shared mailbox is created. It could take about 15 minutes for the shared mailbox to become available.

Step 3: Create a dynamic distribution group

Create a group of valid users so their mail is still sent to them and doesn't go to the catch-all.

Select Recipients, and then select Groups.
Select Add a group.
Select Dynamic distribution, and then select Next.
Note: The dynamic distribution group’s membership list is updated every 24 hours, which means there may be a delay before a newly created user is recognized as a member of the group.
Under Name, enter All users. Select Next.

You will need to click into the description box before the Next button will become available.

Under Owner, select your email address from the list. Under Members, select All recipient types.
Select Next.
Under Group email address, enter allusers (for example, allusers@coolexample.com) before the @, and then select your domain from the list. This is used as the email address.
Select Next.
Verify the details, and then select Create group. You’ll see a success message when the group’s created.
Select Close.

Step 4: Create a rule to catch mail

Create a rule so mail sent to a misspelled or nonexistent email address goes to the catchall@ shared mailbox.

Under Mail flow, select Rules.
Select + Add a rule, and then select Create a new rule.
For Name, enter Catch-All.
Choose the following:

Apply this rule if: Select The sender, and then select is external/internal. Under select sender location, select Outside the organization, and then select Save.
Do the following: Select Redirect the message to, and then select these recipients. Select your shared mailbox (catchall@), and then select Save.
Except if: Select add exception, then The recipient, and then select is a member of this group. Select allusers (your dynamic distribution list), and then select Save.

Select Next.
Select Enforce, and then select Next.
Review the details of your rule and select Finish
Select Done.
Select the rule that you just created and turn on the Enable or disable rule toggle.

Now all mail from outside of your organization will be delivered to this mailbox if the recipient isn't a member of your allusers distribution list. You can come back anytime and change these settings.

Step 5: Decide how you want to access the catch-all

Use one of these options to set up access to the catch-all's email (select a tab to see each option and its instructions).

Deliver mail to a specific user. Since you don't have to check the shared mailbox separately, this is most like the Workspace Email experience.

Select Recipients, and then select Mailboxes.
Select the checkbox next to your catchall@ shared mailbox.
Above your list of mailboxes, select Mailflow setting, and then select Email forwarding.
Turn on the Forward all emails sent to this mailbox toggle.
Under Forwarding address, start to type the email address you want to receive all catch-all messages. Select the email address you want to use after it appears in the dropdown menu.
Note: The email address you are forwarding to must be part of the same organization as the catch-all.
Select Save changes.

The specified email address will now receive all email caught by the catch-all.

To see the catch-all's email separately from a user's mailbox, give users permission to access it as a shared mailbox.

Under Recipients, select Mailboxes.
Select the checkbox next to your catchall@ shared mailbox.
Above your list of mailboxes, select Mailbox delegation. You might need to select the menu to see Mailbox delegation.
Under Read and manage (Full Access), select Edit.
Select + Add members.
Select the checkbox next to the user(s) you want to give access to the shared mailbox.
Select Save.