# Move from Microsoft 365 shared mailbox to Rinhelp

Email in a Microsoft 365 shared mailbox moves through Microsoft Graph, grouped into conversations by each message’s conversationId. Graph allows about 1,000 calls a minute per mailbox, but only four at once.

| Conversations | Time to read them |
| --- | --- |
| 1,000 | about 1 minute |
| 10,000 | about 10 minutes |

Limit used: 1,000 requests a minute (per app per mailbox (10,000 calls in 10 minutes)), about 1 per conversation. Rinhelp takes up to 3,000 conversations a minute. Importing is free: it never emails your customers, never runs Rin and never counts toward a plan.

A Microsoft Entra Global Administrator approves Claude’s Microsoft 365 connector, or gives the AI agent’s app permission to read the shared mailbox. With delegated sign-in, the mailbox’s owner also has to share it with the account the AI agent uses.

## Prompt for a chat app

Using Claude’s Microsoft 365 connector, follow https://rinhelp.com/migrate/microsoft-365.md and first tell me whether you can see our shared mailbox. The connector signs in as me and reads only what my account can, so if it can’t reach the mailbox, I’ll move the history with a coding agent.

## Prompt for a coding agent

Follow https://rinhelp.com/migrate/microsoft-365.md to move our shared mailbox into Rinhelp through Microsoft Graph, with an app that has application permissions or delegated access to it. List messages 1,000 a page, group them by conversationId, and fetch attachments with /$value. Keep to four calls at once on the mailbox.

## Words

| Their word | Rinhelp |
| --- | --- |
| Conversation (conversationId) | Conversation |
| Message | Message |
| Category | Tag |

## What stays behind

- Mail flow rules
- Shared mailbox permissions
- Distribution lists
- Out-of-office settings

## Facts

- Outlook allows each app 10,000 calls in 10 minutes per mailbox, about 1,000 a minute. Vendor page: https://learn.microsoft.com/en-us/graph/throttling-limits (checked 2026-10-31)
- Only four calls can run at the same time on one mailbox, and reading one mailbox doesn’t slow another. Vendor page: https://learn.microsoft.com/en-us/graph/throttling-limits (checked 2026-10-31)
- Graph lists messages 10 at a time by default and up to 1,000 a page on request. Vendor page: https://learn.microsoft.com/en-us/graph/api/user-list-messages (checked 2026-10-31)
- A shared mailbox can be read by an app with application permissions, or with delegated access to it. Vendor page: https://learn.microsoft.com/en-us/graph/api/user-list-messages (checked 2026-10-31)
- Graph returns individual emails, not conversations, so each message’s conversationId is what groups them. Vendor page: https://learn.microsoft.com/en-us/graph/api/message-get (checked 2026-10-31)
- With delegated sign-in, a shared mailbox or folder its owner hasn’t shared with the signed-in user can’t be read. Vendor page: https://learn.microsoft.com/en-us/graph/outlook-share-messages-folders (checked 2026-10-31)
- Adding /$value to an attachment call fetches the file, and attachments that link to cloud files can’t be downloaded. Vendor page: https://learn.microsoft.com/en-us/graph/api/attachment-get (checked 2026-10-31)
- Graph’s mailbox export gives an opaque format with no standard-format option, and Microsoft points to the normal message calls instead. Vendor page: https://learn.microsoft.com/en-us/answers/questions/5748989/how-to-parse-data-received-from-mailbox-export-api (checked 2026-10-31)
- Claude’s Microsoft 365 connector signs in as one person, reads only what that account can, and needs a Microsoft Entra Global Administrator to approve it. Vendor page: https://claude.com/docs/connectors/microsoft/365 (checked 2026-10-31)

## Steps

Import source: `microsoft365`

Connect Rinhelp's MCP server, https://mcp.rinhelp.com/mcp, then follow https://mcp.rinhelp.com/migrate.md step by step with the facts above.

1. [Connect your AI agent](https://docs.rinhelp.com/articles/98a0def1-a07d-4c34-9f19-4d168626b40c-connect-your-ai-agent)
2. [Move to Rinhelp with your AI agent](https://docs.rinhelp.com/articles/5a2a3f45-4e61-4daf-8d23-570a8bfc24a1-move-to-rinhelp-with-your-ai-agent)
3. [Import your help center articles](https://docs.rinhelp.com/articles/a79b3172-a803-44a2-9236-0ab73d56b051-import-your-help-center-articles)
4. [Keep your old help center links working](https://docs.rinhelp.com/articles/ba9cf0f3-9740-4c90-9ca5-7a9a0ef0b450-keep-your-old-help-center-links-working)
5. [Import saved replies](https://docs.rinhelp.com/articles/5d8f8400-2a36-4974-a646-c9f04a41361d-import-saved-replies)
6. [Import past conversations](https://docs.rinhelp.com/articles/7e85f2b0-336d-4774-850a-826951d9585c-import-past-conversations)
7. [Switch your support email to Rinhelp](https://docs.rinhelp.com/articles/44c7935d-ccee-409b-83ac-fa4e5f762eb0-switch-your-support-email-to-rinhelp)
8. [Replace your chat widget](https://docs.rinhelp.com/articles/031f9d71-579b-4229-8f50-3eee8e31c277-replace-your-chat-widget)

## Questions

### Can we use Graph’s mailbox export instead?

No. Microsoft says that export is opaque with no standard format, and points to the normal message calls, which is what the AI agent uses.

### Will attachments that link to cloud files come across?

No. Graph can’t download an attachment that is a link to a cloud file, so that file stays where it is. Ordinary attachments, up to 50 MB each, come across with their emails.

### How long does a Microsoft 365 shared mailbox take?

Graph allows about 1,000 calls a minute per mailbox and a conversation takes about one, so roughly 10,000 conversations take around 10 minutes.

By Wilbert Liu, founder of Rinhelp. Page: https://rinhelp.com/migrate/microsoft-365