How to Include a Teams Channel in an Exchange Distribution List

Following yesterday’s post about the email addresses used by Microsoft 365 Groups and Teams, the following question was asked:

I have an existing email address from my distribution list.
I am using this address for a Microsoft flow “send an email to a SharePoint list”.
The emails send to this email address I also want to place in a teams channel.
1. Can I use my existing email address as an alias from a team channel or
2. can I forward my email sent to the existing email address to a teams channel?

In other words, we have an existing distribution list that we want to add a Teams channel as a member so that anything sent to the list is copied to the channel, including the capture of the messages and attachments in SharePoint.

Simple Solution – an Exchange Mail Contact

The simple solution is to create a new mail contact in Exchange Online using the email address for the channel. Go to the Recipients section of the Exchange Admin Center (EAC), then Contacts, and add a new Mail Contact with the email address of the channel entered in the external email address property (Figure 1).

Creating a new Mail Contact in Exchange Online
Figure 1: Creating a new Mail Contact in Exchange Online

If you plan to allow people to email the distribution list from outside your organization, make sure to configure the list to allow this to happen. You can do this by editing the distribution list properties through the EAC, or by running the PowerShell Set-DistributionGroup cmdlet to set the list’s RequireSenderAuthenticationEnabled property to $False:

Set-DistributionGroup -Identity "Teams DL" -RequireSenderAuthenticationEnabled $False

Exchange Online fully supports the addition of mail contacts in its distribution lists, so it’s an easy step afterwards to update the distribution list with the new contact. You can do this through the EAC or with PowerShell. For example, here’s how to add the contact created above to a DL.

Add-DistributionGroupMember -Identity "My DL" -Member "Teams911"

Any message now sent to the distribution list will be copied to the Team channel. If you don’t want the mail contact to show up in the GAL and OAB, set it to be hidden.

Set-MailContact -Identity Teams911 -HiddenFromAddressListsEnabled $True

More Complicated with Guest Accounts

You can also create a Azure Active Directory guest account for a teams channel email address and when you have the account set up, you can add that account to a distribution list because Exchange Online treats guests as mail users, a valid recipient type for email.

However, Exchange won’t deliver copies of messages sent to the distribution group to a guest member. The reason is that guest accounts don’t appear in Exchange address lists, so Exchange can’t validate that the recipient is in fact valid. Messages sent to the distribution list are delivered to all other members, but the guest account is a black hole.

The workaround is to add the guest to an Office 365 group. Guest accounts are automatically added to the subscribers list of an Office 365 group because email is the way they participate in conversations. If you then add the Office 365 group to a distribution list, routing works as expected because when Exchange checks the recipients, it looks at the Office 365 group and not the individual members. Messages sent to a distribution group that include an Office 365 group with a guest member pointing to a team channel work, but it’s a complicated approach when compared to the simplicity of using a mail contact.


For more information about distribution lists and mail contacts, go to Chapter 7 of the Office 365 for IT Pros eBook. And when you’ve read all that material, go on to Chapter 11 to learn about Office 365 Groups and Chapter 13 to learn about Teams.

8 Replies to “How to Include a Teams Channel in an Exchange Distribution List”

  1. Thanks for this, I’d managed to get this far and it works great for delivering internal email to the channel. However we want email from outside the org to that DL to be posted to the channel too. Message tracking shows it delivered, but it’s not appearing in the channel. Have I missed something?

    1. Same issue here! External email to DL is working fine.. but not delivered to Teams channel. Internal works and delivers to Teams channel.
      I suppose I may have to use the O365 group workaround to get external working correctly?

      1. Do you have any block on the domain used for Teams messages, like us.teams.ms or emea.teans.ms? That might stop messages getting through the Exchange transport system.

      2. No.. if I email directly to the channel’s email address, it generates posts in Teams fine. But when this email is included as part of a DL, it goes into a black hole. I’m attempting the O365 group workaround now… setting up the Teams channel as a guest user, we get the invite emails as posts in Teams. Not sure how to add the O365 group as a member of the DL.. that doesn’t seem to be an option so far.

      3. You should be able to add the group to a DL using PowerShell:

        Add-DistributionGroupMember -Identity DL Member M365Group

      4. That powershell command did work, for adding to the DL.
        However, I still am not getting the email flow to work from external addresses.
        I can email direct to the channel’s email address externally, and it posts fine.
        But even emailing to the O365 group email directly (which has the channel guest account as a member) goes to a black hole.
        Looking in message trace shows it expand the O365 group and then shows delivered to the channel email.. but no post in Teams 🙁

      5. How odd. I fear it’s time to log a support call with Microsoft.

        It looks like the message is leaving Exchange Online and has been delivered to the cloud-only mailbox used for the channel. A connector (from Teams) is supposed to pick up the message from there and post to Teams. You’re absolutely sure that the correct email address is being used?

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