How to Connect Multiple Outlook Accounts to Claude Cowork
Yes, you can connect multiple Outlook or Microsoft 365 work accounts to Claude Cowork with Carly. Connect all your accounts to Carly, add Carly to Claude once, and Cowork works across all your inboxes at once without repeatedly disconnecting Microsoft and signing in again. The same Carly account holds your Gmail inboxes and every calendar on both sides, so you set this up once for all of it.
1. Add your Outlook accounts to Carly
- Sign in at carlyassistant.com.
- Open carlyassistant.com/integrations.
- Find Outlook, click Connect, and authorize the account.
- Click Connect again for the next one, and keep going for as many accounts as you want.
If Microsoft displays Need admin approval, ask the Entra administrator for that tenant to approve the connection, then finish authorization.
Carly connects to thousands of apps, so while you are on that page you can add your calendars, files, CRM, and anything else you want Claude Cowork to reach through the same connector.
2. Add Carly to Claude Cowork
In Claude:
- Click Get the Carly connector, then Connect, and sign in with your Carly account.
- In the Cowork task, open + → Connectors and enable Carly.
Team and Enterprise Owners may need to add the connector at the organization level before members can use it.
What the multi-account setup lets Cowork do
From one Cowork task, you can:
Check this before adding a second connection:
| What you have | Best setup |
|---|---|
| A second Microsoft 365 login from another company | Connect it to Carly |
| Two Microsoft 365 tenants | Connect both to Carly |
A shared mailbox such as billing@ or support@ | Connect it to Carly as its own mailbox |
| A delegated mailbox or folder | Connect it to Carly, or use the primary account’s existing permissions for read-only work |
Native Microsoft 365 versus Carly in Cowork
| Need | Claude’s native Microsoft 365 connector | Carly connector |
|---|---|---|
| Search one work account | Yes | Yes |
| Search its shared mailboxes | Yes, with delegated access | Yes, according to account permissions |
| Use two independent Microsoft accounts | Not in one native connection | Yes |
| Compare Outlook accounts across tenants | No | Yes |
| Send from a selected connected account | Yes when native write tools are enabled | Yes, with the connected account’s permissions |
| Run multi-account workflows | No | Yes |
Anthropic’s current Microsoft 365 setup supports write tools when an administrator enables them. Carly’s advantage here is not merely writing. It is making several independent accounts available to the same Cowork task. Carly offers free Zapier-style workflows; AI agents start at $35/month.
Quick fixes when an Outlook account is missing
| Problem | Fix |
|---|---|
| Microsoft opens the first account again | Choose Use another account and reconnect |
| Microsoft shows Need admin approval | Ask the Entra administrator for that tenant to approve Carly |
| A shared mailbox is missing | Confirm the primary account can open it in Outlook first |
| Carly is installed but absent from Cowork | Open + → Connectors and enable it for the task |
| Claude cannot add Carly | Ask the Claude Owner to enable the Carly connector |
Frequently asked questions
Can Claude Cowork connect multiple Microsoft 365 accounts natively?
Claude supports one authenticated Microsoft account and the shared resources that account can already access. Carly makes multiple independently authenticated Microsoft accounts available within one Cowork task.
Is a shared Outlook mailbox a second account?
No. A shared mailbox is accessed through permissions granted to your primary account. If the second mailbox has its own login or tenant, connect it to Carly too.
Related: What is Claude Cowork · Claude + Outlook · Claude for Microsoft 365 · Manage multiple email accounts with AI · Carly’s Outlook integration
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