Include a Teams Channel Email Address in a DL to Make it Easier for Users to Email
Updated: January 2022
Following yesterday’s post about the email addresses used by Microsoft 365 Groups and Teams, including Teams channel email addresses, 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 email address 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 (new or old) 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).
If you plan to allow people to email the distribution list from outside your organization, make sure to configure the distribution list to allow it to accept messages from unauthenticated senders. You can do this by editing the distribution list properties through the EAC, or by running the 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 an Entra ID 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. Exchange Online treats guests as mail users, which are a valid recipient type for email and supported as distribution lists members.
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 check the validity of the recipient. 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 a Microsoft 365 group. Guest accounts are automatically added to the subscribers list of a Microsoft 365 group because email is the way they participate in conversations. If you then add the Microsoft 365 group to a distribution list, routing works as expected because when Exchange checks the recipients, it validates the Microsoft 365 group and not the individual members. Messages sent to a distribution group that include a Microsoft 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.
So much change, all the time. It’s a challenge to stay abreast of all the updates Microsoft makes across the Microsoft 365 ecosystem. Subscribe to the Office 365 for IT Pros eBook to receive insights updated monthly into what happens within Microsoft 365, why it happens, and what new features and capabilities mean for your tenant.