Often I get this question if a “shared mailbox” can be used in Power Automate to send emails and below concurs:
- What are the advantages and disadvantages?
- Do we need a Microsoft 365 license?
- Is it secure to use a shared mailbox?
- Do we need an account and password in the Power Automate flow?
In this blog post, I will try to answer the questions and provide an answer from my point of view. Of course all feedback and comments are welcome. The following test scenario has been created:
Shared mailbox
- Create a shared mailbox
- Assign different users to the shared mailbox.
- Test access in the mail app.
- Do we see security issues?
Create a Power Automate flow
- Create a Power Automate flow that sends mail from a shared mailbox.
- Procedure to add the action to the flow.
- Do we see security issues?
- Gather the advantages and disadvantages
But first let me explain what a “shared mailbox” is.
What is a “shared mailbox” in Exchange Online?
Shared mailboxes are used when multiple people need access to the same mailbox, such as company information or support email address, reception desk, or other function that might be shared by multiple people.
Users with permissions to the group mailbox can send as or send on behalf of the mailbox email address if the administrator has given that user permissions to do that. This is particularly useful for help and support mailboxes because users can send emails from “Contoso Support” or “Building A Reception Desk.”
More information can be found here.
How to created a “shared mailbox” in Exchange Online?
Open Microsoft 365 admin center and open the view “Shared mailboxes” under “Teams and groups”. Click “Add a shared mailbox”

After creation following steps need to be completed:
- Add members to the shared mailbox
- Manage shared mailbox details
There’s is also the creation of the shared mailbox account under the “Active users” – list, with licenses “Unlicensed”

Add members to the shared mailbox?
On the members item click ‘Edit’

Click ‘Add members’ and select the members that need to have access to the shared mailbox. Click ‘Add’ when the selection of members has been completed.

Adding the “shared mailbox” to the outlook web app.
Open the mail app and right-click the primary email box in the right pane navigation bar.


“Add shared folder” and type to search the “shared mailbox”

Click ‘Add’ to show the shared mailbox in the folder overview.

No password is needed to add the “shared mailbox” to the Microsoft 365 mail app.

Results
Creating a “shared mailbox” is very straightforward. No license is needed for a shared mailbox when the size stays below 50GB. The shared mailbox can only be accessed by people inside the organization. Given access to external people is not possible. A shared mailbox is not intended for direct sign-in by its associated user account. Block sign-in for a shared mailbox account and keep it blocked.
One point can be an issue when an organization would like to send encrypted emails. It’s not possible to encrypt emails sent from a shared mailbox
Create Power Automate flow to send email via the shared mailbox.
In the Power Automate flow below an email is sent via a shared mailbox.

Adding the account, give the possibility to enter:
- Original Mailbox Address: This is the email address of the shared mailbox.
- To: Email address of the person(s) to where the email needs to be sent.
- Subject: Subject of the email.
- Body: email body.
The account that can run this account is a member of the shared mailbox and this member need to have the proper permission to send the email from the shared mailbox.

Running the flow will result in an email that has been sent from the shared mailbox.


Results
Using a shared mailbox to send email from a Power Automate flow is indeed an option if centralization and working as a team is a choice. There’s no need to have a password of the shared mailbox or need of a license.
Just remember that the connection that will be created for the action “Send an email from a shared mailbox (V2)” needs to have an account that has the proper permissions to send emails from that shared mailbox.
Conclusion
Using a shared mailbox for sending emails from a Power Automate flow is easy to set up and depends on the need of the process if a personal – or a shared mailbox will be used. No major concerns can be raised for security because access is given on the user level and direct access is blocked and needs to stay blocked.
Licensing
Who | Min. License | What? |
---|---|---|
User | Exchange Online | Access Shares Mailbox |
Shared Mailbox | None | Max. size of Shared Mailbox 50GB |
Shared Mailbox | Exchange Online Plan 2 | Max. size of Shared Mailbox 100GB |
Shared Mailbox | Exchange Online Plan 1 | with Exchange Online Archive Add-on >> Increase only the archive mailbox |
Shared Mailbox | Additional licenses | – Microsoft Defender For Office 365 – Advanced eDiscovery – Automation retention policy |
When to used?
My suggestion of using a Shared Mailbox in Power Automate is when receiving an email from a person is unnecessary. But that the message is coming from a team, such as Human Resources, Sales, IT department, etc. Love to hear your feedback on this.