Can ChatGPT Access a Shared Mailbox? Yes, Not Attachments
Yes, further than most people expect, with one limit that decides whether it is any use to you. ChatGPT’s Outlook Email app supports shared and delegated mailboxes through dedicated actions and scopes, including Mail.Read.Shared, Mail.ReadWrite.Shared, and Mail.Send.Shared. It genuinely searches a shared mailbox, moves and marks messages in it, and sends from that address rather than yours.
Then: attachments from messages in shared or delegated mailboxes cannot currently be retrieved. OpenAI’s own documentation states the attachment actions work only with messages in the signed-in user’s mailbox.
Read that against what shared mailboxes are actually for. ap@ receives vendor PDFs. orders@ receives purchase orders. claims@ receives documents. The mailbox is frequently a delivery mechanism for files, and files are the one thing ChatGPT cannot pull out of it.
Three limits on ChatGPT’s shared mailbox access
The attachment wall. Covered above, and it is not a permission you can grant your way past. It is a limit on the actions themselves.
You have to name the mailbox owner. OpenAI requires the exact mailbox owner email, the UPN, on every shared-mailbox request. Fine once you know it, and a reliable source of silent wrong-mailbox answers when a team has several similar addresses and someone guesses.
Two separate approvals, by two different people. The scopes need organization-wide consent from a Microsoft Entra administrator, and the actions then need enabling by a ChatGPT workspace owner or admin under Action control. OpenAI notes those may be different people, and that users can need to reconnect the account after permissions change. On a managed tenant this is where most evaluations quietly end.
Two smaller edges: Outlook write actions are unavailable through Company Knowledge, and the calendar app requests shared calendar scopes while its own limitations section calls event data read-only. Treat shared-calendar writing as unsettled rather than trusting either half.
ChatGPT does not act when mail arrives
ChatGPT's Scheduled Tasks and Claude's Cowork tasks run on a clock. Hourly, daily, weekly, whatever you set. Nothing else starts them, so the lead who emails at 9:05 waits, and so does the form that just landed. Carly is already watching across the thousands of apps it connects to, and moves the moment it happens.
Everything above happens because you opened a chat and asked. A shared inbox fills overnight, over a weekend, and while the person who owns it is in a meeting. Search and send are the easy half. The half that matters is something noticing the message when it lands.
ChatGPT, Claude, Copilot and Carly on a shared mailbox
| Read a shared mailbox | Reply from that address | Attachments inside it | Starts on arrival | |
|---|---|---|---|---|
| ChatGPT | Yes | Yes | No | No |
| Claude | Yes, read-only | No | Not through a write path | No |
| Copilot Chat | Yes | Drafts, you send | Within Outlook | No |
| Carly | Yes | Yes | Yes | Yes |
Claude’s Microsoft 365 connector reaches shared mailboxes on Mail.Read.Shared with no matching send permission, so it reads and cannot answer. Details in Can Claude access a shared mailbox?. Copilot Chat became generally available in shared and delegate mailboxes between early May and early June 2026, doing Summarize and Draft with no special prompt syntax, not yet in classic Outlook for Windows.
Run the shared mailbox with Carly instead
Carly is the only row above with a Yes in every column. It authorizes a shared mailbox as a mailbox in its own right, opens the attachments ChatGPT cannot reach, and replies from that address without waiting for you.
- Sign in at carlyassistant.com.
- Open carlyassistant.com/integrations and click Connect on Outlook.
- Authorize the account that already has access to the shared mailbox. Carly uses the delegate rights Microsoft has already granted, so no new permission has to be invented for it.
- Confirm the shared mailbox appears in Carly’s mailbox list beside your own, carrying its own address.
- Name its role, such as AP, Support, or Orders.
Then describe the queue:
Work the AP mailbox every hour. Parse each vendor PDF for vendor, amount, and due date, log new ones in the invoice tracker, and reply to anything missing information with the specific question.
That prompt is only possible because the PDF can be opened, which is exactly where ChatGPT stops. It runs with nothing open and the reply carries the shared address. Carly connects to thousands of apps, so the same pass writes to accounting, updates the CRM, and notifies an owner in Slack. Free Zapier-style workflows; AI agents from $35/month. Start at carlyassistant.com.
Both examples exist as worked builds: vendor invoice triage and the Outlook escalation queue.
Frequently asked questions
Can ChatGPT read a shared Outlook mailbox?
Yes. The Outlook Email app supports shared and delegated mailboxes through dedicated actions and scopes, and you supply the exact mailbox owner email on each request.
Can ChatGPT send from a shared mailbox?
Yes. The app requests Mail.Send.Shared, so mail goes out from the shared address rather than your own, once an admin has approved the scopes and enabled the action.
Why can’t ChatGPT open attachments in a shared mailbox?
OpenAI documents the attachment actions as working only with messages in the signed-in user’s mailbox. It is a limit on the actions rather than a permission you can add.
Does connecting a shared mailbox need an administrator?
Usually two. A Microsoft Entra administrator grants the scopes for the organization, and a ChatGPT workspace owner or admin enables the actions.
Can ChatGPT reply to a shared inbox automatically as mail arrives?
No. It acts inside a chat you start. Carly runs the mailbox on arrival, attachments included, and answers from the shared address.
More: Can Claude access a shared mailbox? · AI for shared mailboxes · Best shared inbox tools · Can ChatGPT access Outlook? · Can ChatGPT send email attachments?
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