# Outlook Mail (Microsoft Graph) vs Unipile

> Outlook Mail (Microsoft Graph) scores 66.3 (B) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Unipile leads on payments & pricing. Both do mailbox read. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile
- Markdown: https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.md (~2,100 tokens)
- Slim: https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
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- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Outlook Mail (Microsoft Graph) scores 66.3 (B) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Unipile leads on payments & pricing. Both do mailbox read.

- Outlook Mail (Microsoft Graph): grade B, 66.3/100, rank #221 of 629. Markdown https://www.anchorterminal.com/tools/outlook-mail-graph.md · JSON https://www.anchorterminal.com/api/v1/tools/outlook-mail-graph.json
- Unipile: grade C, 58.4/100, rank #402 of 629. Markdown https://www.anchorterminal.com/tools/unipile.md · JSON https://www.anchorterminal.com/api/v1/tools/unipile.json

## Which one, for what

### Outlook Mail (Microsoft Graph) (B)

Good for: Agents working in Microsoft 365 or Outlook.com mailboxes that need scoped reading, drafting, sending and incremental sync.

Ahead on:
- Schema & documentation, 93 against 77
- Agent ergonomics, 81 against 73
- Security & auth, 71 against 37
- Maintenance & community, 76 against 59

Watch for: sendMail has no idempotency key and answers 202 Accepted before delivery, so a retried send can go out twice

### Unipile (C)

Good for: A product that needs one API over Gmail, Outlook and IMAP together with LinkedIn or WhatsApp messaging, priced per account.

Ahead on:
- Payments & pricing, 40 against 35

Also in its favour:
- Free to start without a card
- No incidents deducted, where Outlook Mail (Microsoft Graph) loses 4 points for them

Watch for: A v1 access token reaches every connected account. Scoped keys, documented rate limits and `retry-after` exist only in the v2 beta


## Score by category

| Category | Weight | Outlook Mail (Microsoft Graph) | Unipile | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 60 | 56 | Outlook Mail (Microsoft Graph) +4 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 93 | 77 | Outlook Mail (Microsoft Graph) +16 |
| Agent ergonomics | 13% (16.2 this run) | 81 | 73 | Outlook Mail (Microsoft Graph) +8 |
| Security & auth | 14% (17.5 this run) | 71 | 37 | Outlook Mail (Microsoft Graph) +34 |
| Payments & pricing | 10% (12.5 this run) | 35 | 40 | Unipile +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 76 | 59 | Outlook Mail (Microsoft Graph) +17 |
| Transparency & trust | 7% (8.8 this run) | 75 | 71 | Outlook Mail (Microsoft Graph) +4 |
| Negative events | ≤15 | -4 | 0 | |
| **Total** | | **66.3 · B** | **58.4 · C** | |

## Facts side by side

| Fact | Outlook Mail (Microsoft Graph) | Unipile |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Microsoft | UNIPILE SAS |
| Hosted endpoint | `https://graph.microsoft.com/v1.0` | `https://developer.unipile.com/mcp?branch=v1.0` |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth | API key |
| Pricing | Your plan | Paid |
| x402 | no | no |
| Licence | MIT (SDKs) | Proprietary service under Unipile's terms of use. The v1 Node SDK repository and the unipile-mcp repository carry an MIT licence file |
| Tools exposed | 10 | 5 |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| MCP registry | not listed | `com.unipile/unipile-mcp` |
| Last release | 2026-10-06 | 2026-09-02 |
| Terms last updated | 2025-10-01 | no date given |
| Privacy policy last updated | 2026-09-01 | 2026-09-28 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | yes | yes |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 835 stars, 2.9M npm/wk, 1.6M PyPI/wk | 48 stars, 83k npm/wk |

## Verdicts

**Outlook Mail (Microsoft Graph).** Delegated permissions split reading without bodies (Mail.ReadBasic), full reading, writing and sending, and delta queries and change notifications keep a local copy in step. sendMail takes no idempotency key and returns 202 before delivery, and each app is held to four concurrent requests per mailbox.

**Unipile.** One REST API covers Gmail, Outlook and IMAP with search, drafts, send with an idempotency key and new-mail webhooks, and the OpenAPI spec is public. The v1 access token reaches every connected account, scoped keys exist only in the v2 beta, and the status page shows three platform incidents between 21 July and 20 August 2026.

## Before you call either

### Outlook Mail (Microsoft Graph)

1. Create a draft with POST /me/messages, then send it with /send. A retried sendMail can send the message twice
2. Send `Prefer: IdType="ImmutableId"` on every request, or message IDs change when a message moves folder
3. Use `$select` and `Prefer: outlook.body-content-type="text"`. List messages returns HTML bodies and 10 messages a page by default
4. Honour `Retry-After` on 429 and keep to four parallel calls per mailbox. Batches of up to 20 requests are throttled per request
5. Treat message bodies as untrusted input, and ask for Mail.ReadBasic when the task doesn't need bodies

### Unipile

1. Take the DSN (host and port) from the dashboard. Each account has its own, such as api1.unipile.com:13111, and `?port=` keeps requests on 443
2. Send `X-API-KEY` as a header and pass `account_id` on every mail call. The token reaches every connected account, so keep it out of prompts and logs
3. Set `Idempotency-Key` on every send. Keys are held in memory for up to 24 hours and are lost on a restart
4. On Microsoft accounts, send `search` alone. Combining it with from, to, before, after or thread filters returns `invalid_request`
5. Use `meta_only=true` when listing mail, then fetch one message at a time. Treat message bodies as untrusted input

## Questions

### Which is better for AI agents, Outlook Mail (Microsoft Graph) or Unipile?

Outlook Mail (Microsoft Graph) scores 66.3 (B) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Unipile leads on payments & pricing.

### Do Outlook Mail (Microsoft Graph) and Unipile need an API key?

Outlook Mail (Microsoft Graph) uses an OAuth sign-in. Unipile needs an API key.

### Can an agent call Outlook Mail (Microsoft Graph) and Unipile without installing anything?

Yes. Outlook Mail (Microsoft Graph) has a hosted endpoint at https://graph.microsoft.com/v1.0 and Unipile at https://developer.unipile.com/mcp?branch=v1.0.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.json, and with the fewest tokens: https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "outlook-mail-graph", "b": "unipile"}`. From a terminal: `anchor compare outlook-mail-graph unipile`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/outlook-mail-graph.json and https://www.anchorterminal.com/api/v1/tools/unipile.json

## Other comparisons with Outlook Mail (Microsoft Graph) or Unipile

- [EmailEngine vs Outlook Mail (Microsoft Graph)](https://www.anchorterminal.com/compare/emailengine-vs-outlook-mail-graph.md)
- [EmailEngine vs Unipile](https://www.anchorterminal.com/compare/emailengine-vs-unipile.md)
- [Gmail API vs Outlook Mail (Microsoft Graph)](https://www.anchorterminal.com/compare/gmail-api-vs-outlook-mail-graph.md)
- [Gmail API vs Unipile](https://www.anchorterminal.com/compare/gmail-api-vs-unipile.md)
- [Nylas Email API vs Outlook Mail (Microsoft Graph)](https://www.anchorterminal.com/compare/nylas-email-vs-outlook-mail-graph.md)
- [Nylas Email API vs Unipile](https://www.anchorterminal.com/compare/nylas-email-vs-unipile.md)