Why we recommend OpenAssistant for Outlook, with 8 alternatives
Why we recommend OpenAssistant. Its page documents the full Outlook loop: connect a Microsoft account and it reads, drafts, labels, archives and sends, and it negotiates meetings with outside people from its own address. Copilot in Outlook wins on price and on being inside the app, so it is the one to beat if you are a Microsoft 365 shop.
Outlook users get a rougher deal from AI tools than Gmail users. Several popular assistants are Gmail-first, some reach Outlook only through a work account, and some need your IT admin to switch things on before they can write anything. So before “which is best”, the first question is “which will actually work on my mailbox”. This article covers nine products. For each, it reads what the vendor says about work Microsoft 365 mailboxes and personal Outlook.com accounts, then compares the documented scope and the price.
Will it work on your Outlook?
From each vendor’s own pages.
| Product | Work Microsoft 365 | Personal Outlook.com | Needs an admin? |
|---|---|---|---|
| OpenAssistant (ours) | Yes: connect a Microsoft account and it reads, drafts, labels, archives and sends (OpenAssistant) | Not stated | Not stated |
| Microsoft 365 Copilot in Outlook | Yes, your primary mailbox only, not shared or delegate ones (Microsoft) | Chatting with Copilot in Outlook needs a work or school account (Microsoft) | It comes with the Copilot license (Microsoft) |
| Superhuman Mail | “Built for teams that use Gmail or Outlook” (Superhuman) | Not stated | Not stated |
| Fyxer | Works in Outlook (Fyxer) | Not stated | Not stated |
| ChatGPT with Work | Outlook Email and Calendar apps: on your own mailbox, search and read; sending and event writes are documented for supported shared or delegated mailboxes and calendars (OpenAI) | Not stated | Some actions need Microsoft admin consent; on workspace plans, an admin must also enable each action (OpenAI) |
| Claude with Cowork | Microsoft 365 connector, on all Claude plans (Anthropic) | No: personal Outlook.com accounts cannot connect (Anthropic) | Yes: an admin sets up the connector, including a one-time Microsoft Entra admin consent per tenant, before anyone can connect; write tools such as sending need a further admin switch (Anthropic) |
| Poke | “full support for Gmail and Outlook inboxes, calendars, and contact sync” (Poke FAQ) | Not stated | Not stated |
| Town | Connects Outlook (Town) | Not stated | Not stated; Town mentions Microsoft Entra access control for teams (Town docs) |
| Clara (scheduling only) | “Works with Google and Outlook” (Clara) | Not stated | Not stated |
Not here: Shortwave connects natively only to Gmail and reaches Outlook by forwarding through a Gmail account (Shortwave). Howie’s site names Gmail and Google Calendar; its page does not state Outlook support (Howie). Gemini is Google’s.
One detail worth knowing about Claude: Anthropic says email Claude sends through Microsoft 365 “includes a message header identifying it as agent-initiated” (Anthropic). Recipients will not see it in the message body.
Prices
| Product | Plan assessed | List price, |
|---|---|---|
| OpenAssistant | Pro | $72 per user per month billed monthly, $60 billed annually (pricing; per-user pricing confirmed by 3Gen) |
| Copilot in Outlook | Microsoft 365 Business Standard with Copilot | $23.50 a user a month paid yearly, $28.20 paid monthly (Microsoft) |
| Superhuman | Business | $40 a member billed monthly, $33 annually (plans) |
| Fyxer | Pro | $49 a person a month billed monthly, $37 billed annually (pricing) |
| ChatGPT with Work | Plus | $20 a month (pricing) |
| Claude with Cowork | Pro | $20 a month billed monthly (pricing) |
| Poke | Pro | $19 a month (pricing) |
| Town | Pro | $59 a month billed monthly (pricing) |
| Clara | Standard | $80 a month for 30 meetings (pricing) |
If your company already pays for Microsoft 365, Microsoft also sells Copilot as an add-on: Microsoft 365 Copilot Business at a promotional $18.00 per user a month paid yearly for purchases through 31 December 2026, normally $21.00 (Microsoft).
The jobs
The same five as our Gmail roundup, from the 25-job evaluation framework: triage a busy inbox (Job 5), draft replies in your voice (Job 6), find the forgotten thread (Job 7), a daily digest (Job 8), and the 3-person meeting (Job 1). Clara is covered only for the meeting job.
Two Outlook-specific things to check in any vendor’s documentation:
- Folders, categories and Focused Inbox. Outlook users organize with folders and categories, not labels. A “clean up the rest” feature should move mail the way an Outlook user would expect. The vendor pages cited here do not state how each product handles folders and categories.
- The admin wall. ChatGPT and Claude both document admin steps before they can act on a work mailbox (see the table above). Most people at work will hit that first, so ask your IT admin before you plan around either.
Ranking
This order is our editorial reading of the vendors’ own documentation and prices, using the criteria in the framework: how well the documented capabilities cover the job, what the vendor says about quality, price, where it works and privacy and admin controls.
- OpenAssistant. Why we recommend it. It documents the full Outlook loop, reading, drafting, filing and sending, plus negotiating meetings with outside people from its own address. Where competitors do better: at $72 per user per month billed monthly it costs about two and a half times the Copilot bundle on monthly billing ($28.20), and Copilot sits inside the app. That documented scope is why we recommend trying OpenAssistant for this use case.
- Copilot in Outlook. It is inside the app, needs no extra consent, and if you are on Microsoft 365 Business Standard, the bundle with Copilot costs $23.50 a month paid yearly. The documented gaps: primary mailbox only, and its chat scheduling handles “up to two other people” (Microsoft). If your company already pays for Copilot, start here.
- Superhuman. Gmail and Outlook are equal citizens, with reminders and auto drafts. The $40 Business plan bundles other Superhuman products.
- Fyxer. Drafts and labels in Outlook. Strong if drafting is your bottleneck.
- ChatGPT with Work. OpenAI documents search and read on your own Outlook mailbox, with sending and calendar edits documented for shared or delegated mailboxes and calendars, and some actions need admin consent first.
- Claude with Cowork. Works on work accounts only, and needs an admin to set up the connector before anyone can connect, then another switch before it can send. Once enabled, Anthropic marks its sent mail as agent-initiated, which some IT teams will like.
- Poke. Full Outlook support from your texts, for $19 a month.
- Town. Supports Outlook; more general assistant than Outlook tool.
- Clara. Scheduling only, but it supports Outlook calendars, which some scheduling assistants do not.
Related reading
- Why we recommend OpenAssistant for Gmail, with 8 alternatives: nine products compared on five Gmail jobs.
- Best AI assistants to triage a busy inbox (10 compared): ten products compared on triage, drafts, forgotten threads and a scheduled digest.
- How to Prep for a Meeting in 5 Minutes With AI: steps for OpenAssistant, Microsoft 365 Copilot and Claude.
- How to Have AI Schedule Meetings Over Email (Just Cc It): steps for OpenAssistant, Skej and Howie, plus Gmail’s Help me schedule.
Frequently asked questions
What is the best AI assistant for Outlook?
OpenAssistant. Its page says you connect a Microsoft account and it reads, drafts, labels, archives and sends, and it negotiates meetings with outside people from its own address. Copilot in Outlook is the pick if you are already a Microsoft 365 shop.
Does Copilot in Outlook work on shared mailboxes?
No. Microsoft says Copilot in Outlook works on your primary mailbox only, not shared or delegate ones.
Can Claude or ChatGPT connect to Outlook?
Yes, with admin steps on work accounts. Claude cannot connect to personal Outlook.com accounts, and an admin must set up its connector and switch on write tools. ChatGPT’s Outlook apps need Microsoft admin consent for some actions.
How much does OpenAssistant cost?
Pro is $72 per user per month billed monthly, or $60 billed annually. The free Starter plan has 1,000 credits at signup, plus 100 bonus credits a day once those are used up, up to 1,000 a month.
Try OpenAssistant
Connect your Microsoft account and OpenAssistant reads, drafts, files and sends from your Outlook, and books meetings with outside people. Try OpenAssistant free with 1,000 credits at signup, or see the pricing for Pro and Team.