Office 365 Groups Mail doesn't allow me to capture Email Subject

Hi Siti Aisyah

Thank you for reaching out to Microsoft Q&A

The behaviors you are experiencing with subject lines and reply detection are due to the Office 365 Groups Mail connector's restricted trigger output. Unlike the Outlook connector, the Groups Mail trigger does not expose the message body or standard email fields directly, additional actions such as "Get a thread post" are required to retrieve them. This makes building a reliable ticketing flow significantly more complex compared to a standard Outlook-based approach.

There are two workaround approaches you can try in this situation:

Approach 1: Workaround within the Groups Mail trigger (no admin access required)

For the subject line, reference it manually via the expression triggerOutputs()?['body/subject'] rather than relying on dynamic content chips.

To prevent replies from generating duplicate tickets, store the conversationId from the trigger (triggerOutputs()?['body/conversationId']) in a dedicated column in your SharePoint list.

On each trigger run, use a "Get items" action filtered by that conversation ID, if a matching record already exists, skip ticket creation.

Approach 2: Migrate to a Shared Mailbox trigger

If your admin can configure forwarding from the M365 Group mailbox to a shared mailbox, replace the Groups Mail trigger with the Outlook connector's "When a new email arrives in a shared mailbox" trigger.

Hope my answer will help you.

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Office 365 Groups mail and SharePoint site mailboxes have limitations that affect using them as a robust ticketing source compared to a regular Outlook mailbox.

Key points from the available information:

1. SharePoint sites connected to Microsoft 365 groups receive email via the group address, and those messages are treated differently from normal user mailboxes. For example, notifications to such groups can even be blocked by default when coming from certain senders, and group settings must be adjusted to allow external senders.
2. The Power Automate email experience and triggers are designed primarily around Outlook mailboxes (for example, using When a new email arrives (V3) on an Outlook mailbox) rather than group mailboxes or site mailboxes. The documentation and troubleshooting guidance focus on Outlook/Office 365 Outlook connectors for reliable access to email properties such as Subject, From, and so on.
3. The email-trigger guidance explicitly recommends using the Outlook-based trigger and filtering on properties (Folder, To, CC, From, Subject Filter, etc.) at the trigger level to build flows that respond to incoming messages and then act on their properties.

Given this, the most reliable way to:

• capture the Subject line,
• and implement ticket de-duplication (for example, by checking conversation/thread properties or subject patterns),

is to keep using an Outlook mailbox–based trigger (such as When a new email arrives (V3) on a standard mailbox) instead of the Office 365 Groups Mail trigger. The Outlook trigger exposes the email properties described in the documentation and is the supported pattern for email-driven flows.

For a group or site scenario, a common pattern is:

• Deliver mail to a normal mailbox (or shared mailbox) that is the flow’s trigger source, and
• Use rules or addressing (To/CC) so that messages sent to the group or site address are also delivered or forwarded to that mailbox, where the Outlook trigger can read full properties and drive the ticketing logic.

Where group mail is required, the limitations of the Office 365 Groups Mail trigger mean it will not behave like a full Outlook mailbox trigger and may not expose all properties or support the same level of control needed for a ticketing system.

References:

• Trigger a cloud flow based on email properties
• Notifications sent to SharePoint sites connected to Microsoft 365 groups aren’t received