Recently I had the following challenge: we created a private Team to discuss confidential matters at work, but we wanted people that were not Team members to be able to send concerns / suggestions by email.

Additionally, if those emails were automatically converted to a Trello card and a new thread in Teams, would be great, wouldn’t it? I found a way to do it but with the way Office 365 Groups are configured, it’s not that easy. I needed to create a custom rule in Exchange Online. The steps are detailed in this post.

Solution: custom exchange rules

Getting the Trello and Teams integration emails

You can automatically create a Trello card by sending an email to the board. The settings can be found in Menu > More > Email-to-board Settings:

In Teams, you can also create threads by sending an email to the dedicated channel address:

Adding external emails to O365 Group is not possible

At first, I thought it would be easy. I just need to get the Trello integration email address and the Teams channel email address, add them to the O365 Group, and voilà, it’ll work! Unfortunately, this can be done with Distribution lists, but not O365 Groups.

Creating a rule in the Exchange admin center

It’s a bit dirty, but the workaround I found was the following. First, I created contacts for my Channel Address and my Trello address in O365 Admin Portal > Users > Contacts:

Then, I created a rule in Exchange admin center > mail flow > rules:

That’s it! When someone sends an email to the group, it gets copied to both Trello and Teams!

Results

Here’s an email I sent to my O365 Group email address:

It got delivered to my Teams channel:

… and a card got created in my Trello board!

Wait! There’s another workaround

Another way of achieving similar results is to register the Trello and Teams contacts as Guest Users in Azure Active directory, and then add these “fake” users to the O365 Group. The flow goes like this:

1. Create a new Guest User in Azure AD
2. Assign the Trello or Teams Channel email to the user
3. Catch the registration email (in Trello or Teams) and complete the registration process for the user (you’ll need to assign a password!)
4. Add the fake users to your Office365 Group in Azure AD or Teams

Thanks to Guillaume Petitclerc from Moov.AI for this tip!

This should be easier!

Both approaches are workarounds / hacks and have their pros and cons. Creating Guest Users just for a enabling a notification seems a bit overkill and could lead to security concerns and proliferation of fake users in the AD. The Exchange rule is only visible to an Exchange Admin so these rules are hard to track and maintain by the Team. Is there something more annoying than debugging something nobody knows even exists!? Hopefully, Microsoft will allow an easier way of adding notification emails to an O365 Group in the future!