How to See Who Replied to a Shared Mailbox Email in Outlook

Short answer: Outlook has no built-in feature that shows which teammate replied to a shared mailbox email. You can find the actual sender by checking the shared Sent Items folder or by running an admin message trace in Exchange, but neither is quick or practical at a glance. The more useful fix is to make the inbox accountable in the first place — so you can see who owns each email and who closed it — with an assignment-and-history layer such as SBX on top of the mailbox.

Why Outlook can't tell you who replied

A shared mailbox is designed so the whole team sends as one address. When a customer emails support@ and a teammate answers, the reply goes out from support@ — Outlook deliberately hides the individual sender so the customer only ever sees the role address. That's good for a consistent customer experience, but it means Outlook stores no visible record of which person hit send. There is no "replied by" column, no owner field, and no activity log on a native shared mailbox or Microsoft 365 Group.

Native workarounds (and their limits)

Check the shared Sent Items folder

If replies are being saved to the shared mailbox, open its Sent Items folder to confirm a message was answered. For sent copies to land there, an admin must enable it with the MessageCopyForSentAsEnabled setting; otherwise Send As replies never reach the shared Sent Items at all. The catch: the Sent Items entry is attributed to the shared address, not to the person who sent it, so you can confirm that a reply went out but not easily who wrote it.

Run a message trace in Exchange

An administrator can use message trace in the Exchange admin center to look up a specific message and see which account sent it. This does reveal the individual sender, but it's an admin-only, one-message-at-a-time investigation — useless for the everyday question of "has anyone answered this yet?"

Rely on manual conventions

Some teams add a category or type their initials to signal "I've got this." It works only as long as every person remembers to do it every time, and it leaves no trustworthy history when someone forgets.

SBX won't tell you which teammate physically hit send — no shared-mailbox tool records that without a message trace — but it removes the reason you're usually asking. Every email carries an assignee and an open/closed status, and each change — assigned, reassigned, closed, reopened — is written to an activity log with the person's name and a timestamp. So you can open any email and immediately see who owns it, who closed it, and what happened along the way.

Prevent the problem instead of investigating it

The deeper issue isn't just finding out who replied after the fact — it's that without visible ownership, two people can answer the same email, or everyone assumes someone else has.

Because SBX gives each email a clear owner and status, teammates can see at a glance what's already handled and what's still open. And with the browser extension, collision detection warns you in real time if someone else is already writing a reply to the same message, so duplicate answers don't reach the customer.

Frequently asked questions

For Microsoft's reference on tracing sent messages, see Run a message trace and, for who's involved in a shared address, our comparison of Microsoft 365 Group vs shared mailbox vs distribution list.