Comparison

Try the native one first

We sell an email MCP server, so take the opening recommendation in that light and then check it against the table further down: if your mailbox is a Gmail or a Microsoft 365 work mailbox and you want searching, summarising and drafting, start with your assistant's own connector. It is included in a subscription you already pay for, it takes one sign-in, and for that job it works.

This page is about the cases where it does not, and there are more of them than the marketing suggests. They fall into two questions, and both are answerable from the vendors' own documentation rather than from anybody's opinion.

The two questions it turns on

Can it act, or only read

This is not the clean split you would expect, and the ranking is surprising. The product that acts on a mailbox most thoroughly is Microsoft's, and it is the one that does not send. Microsoft's own triage page is explicit about what happens:

Microsoft Copilot helps you triage your email by using natural language commands in Copilot chat. Copilot performs the requested action and updates your mailbox in Outlook automatically.

Microsoft, Triage email with Copilot in Outlook

The list that follows it is long: pin, flag, set a reminder, mark read or unread, archive, delete, move, copy, junk, categories, create folders, inbox rules. Read that as the high-water mark for filing, because nothing else here comes close. What it does not include, anywhere on any page we could find, is sending. The drafting flow ends with a person pressing Send, which Microsoft describes as deliberate.

Anthropic's is the opposite shape, and it is the most checkable of the lot because Anthropic publishes the actual tool list for the Microsoft 365 connector. It sends, forwards, drafts, trashes and applies categories. There is no move-to-folder tool, no flag tool and no mark-read tool. Not "undocumented": absent from a published list, while the permission scope the connector requests is described as covering moving and labelling. It can send your mail but it cannot file it.

Anthropic's Outlook add-in is a third product again, with a third answer, and its documentation contains the single most useful sentence any vendor published on the day we read them:

Claude never sends mail or invites on its own. The add-in does not request the Mail.Send permission. Every draft lands unsent in Outlook's compose or appointment form, and you click Send.

Anthropic, Claude for Outlook

That is how a capability statement should read, and it is worth pausing on why. It does not say "Claude will ask before sending", which is a policy that can change; it names the permission that was not requested, which is a fact about the software that you could verify on the consent screen yourself. Every other line in this section had to be pieced together from scope lists and absent tool names. That one is simply stated. It is also the product that does move and flag, which the M365 connector does not, so three Anthropic mail products give three different answers and the names do not tell you which is which.

Which mailboxes it can reach

Here the answer is clean, and it is the same for all of them: each vendor's connector reaches that vendor's own mail and nothing else.

• Anthropic

  Google accounts, or an Entra work tenant

  The Microsoft 365 connector states that it requires a Microsoft Entra tenant tied to a business plan, and that personal Microsoft accounts such as outlook.com and hotmail.com addresses cannot be used. It refuses even Microsoft's own consumer mail.

• Microsoft

  Primary Exchange Online mailboxes only

  Not an archive mailbox, not a group mailbox, not a shared or delegate mailbox, and not Exchange on-premises, where the icon appears but is greyed out. There is one documented edge: a licensed work identity in the new Outlook extends Copilot to Gmail, Yahoo and iCloud accounts connected on the same device, which is an entitlement travelling with the identity rather than Copilot reaching a non-Microsoft mailbox.

• Google

  Google accounts, and it is closing the other doors

  Gemini reaches Gmail. And the route people have used to get other mail into Gmail is being withdrawn on a published timetable: Google's own support page gives January 2027 for the end of Send-as for third-party accounts, Gmailify and POP fetching, and says a third-party account can no longer be added or synced in Gmail on the web.

No vendor ships an IMAP connector. If your mail is on your own domain at a web host, on Fastmail, on Zoho, on a cPanel server, or anywhere else that is not Google or Microsoft, no native connector reaches it, and the documented route is a custom remote MCP server. That is the gap this product was built for, and it is worth being precise that the gap is about the mailbox rather than about capability.

The capability table

Every cell read from the vendor's own documentation on 30 August 2026. NS means not stated, and it is doing real work: a no is a vendor documenting a limit, and NS is us declining to fill in a blank they left. Several of the NS cells are things the product may well do.

This table compares MCP with the connectors built into the assistants. If you have already decided on an MCP server and want to know how the hosted ones differ from each other, that is a separate table: email MCP servers compared.

Read 30 August 2026 Three of the source sites could not be read by an automated fetch and were read in a browser instead, and six Google support pages had to be read from archived captures of Google's own pages because the live ones served a challenge. The sources are listed at the foot of this page and the full record, with capture dates, is in our research notes.

Two rows deserve expanding rather than living in a cell. Sending with attachments is a real limit on both sides. Anthropic's Microsoft 365 connector rejects it outright: its own security guide says attachments are not supported in any write tool, and sending, forwarding and drafting all reject messages that carry one. Ours takes a file that is already in your mailbox, one at a web address, or one from your own computer through a one-off upload link, and none of the three passes through the model: each is fetched at send time, inside the same 10 MB whole-message ceiling a mail client would apply. Only a file the assistant composes itself is limited to a few tens of kilobytes, for a reason that is a property of language models rather than of our code.

Reading attachment content is the row where we say no and two of the native connectors say yes, and it is worth being plain about why rather than burying it. No tool here returns the bytes of an attachment to a model: an attachment comes back as its name, type and size, a reference for attaching it to another message, and a link. The bytes would have to travel through the conversation to reach the model, which is the same reason a file the assistant writes itself has to be tiny. So it cannot tell you what a PDF says. What it can do, and what nothing else on this table documents doing, is hand you the file: every attachment comes back with a link that streams it straight from your mail provider for fifteen minutes, so an assistant that cannot open the invoice can still put it in front of you.

The question nobody answers

Here is the finding that surprised us most, and it is a gap rather than a failing: no vendor states, either way, whether reading a message marks it as read.

Across five products and every page read on 30 August 2026, the only statement about read state anywhere is ChatGPT's Outlook app being able to mark messages in a shared mailbox read or unread when you ask it to. What an ordinary read does to the seen flag is documented by nobody.

It matters more than it sounds. Ask an assistant to go through eighty unread messages and tell you which need you, and if reading sets the flag, you have just lost the only marker you had for what you personally have not looked at. There is no undo for that at scale. It is the difference between a triage assistant and one that quietly empties your unread list.

Where the vendors contradict themselves

Worth knowing if you are trying to work out what your own connector does, because you will find both halves and the second one will not look like a contradiction until you have seen the first. These are all on the vendors' own sites.

• Anthropic, Gmail

  Can it write, or can it not

  The help centre and the public connector directory both say Claude can send, reply and forward from Gmail. The developer documentation for the same connector carries a limitations warning reading that Claude cannot create, send or modify emails. The help centre also says the connector is available for all users, while the developer docs name Pro, Max, Team and Enterprise.

• Anthropic, Microsoft 365

  Read-only, on a page listing write permissions

  The set-up article's permissions reference opens by saying permissions are read-only and that Claude cannot modify, delete or create content in your tenant. Further down the same page it lists Mail.Send, Mail.ReadWrite and MailboxSettings.ReadWrite under a heading of write permissions.

• OpenAI, Outlook

  No writes in the list, write scopes in the request

  The capability list for the Outlook app contains no write action on messages in your own mailbox. The scopes it requests include Mail.ReadWrite and Mail.Send, and a release note says ChatGPT can draft and send from a connected Outlook account.

• Microsoft, the free tier

  Not grounded in your email, except when it is

  The Copilot overview says Copilot Chat is not grounded in organisational content like files, emails or chats. The Outlook chat page says unlicensed users can take action directly in Outlook, and offers "Flag all unread emails from my manager" as an example prompt.

None of this is bad faith. These are large products documented by different teams at different times, and mail capability has been moving monthly. It does mean that if you want to know what your connector actually does, the reliable move is to test it on a message you do not mind losing rather than to read about it.

Which one you actually want

Three honest answers rather than one.

• Use the native connector

  Gmail or a work Microsoft 365 mailbox, and you want reading and drafting

  It is included, it takes a sign-in, and it does that job. There is no argument for paying us anything on top of it. If you later find it will not file or flag, come back to the table above and check whether that is documented or merely absent.

• Use an MCP server

  Any other mailbox, or you want filing as well as reading

  Your own domain, a web host's mailbox, Fastmail, Zoho, a personal outlook.com address, anything on IMAP. No native connector reaches any of those. And where filing matters, an MCP server gives you move, flag, mark read and mark unread as ordinary tools rather than as a gap in a published list.

• Use both

  You have more than one mailbox, which most people do

  They are separate tools in the same client and they do not conflict. A work Microsoft 365 account through your assistant's own connector and a personal or business mailbox through this one is a perfectly ordinary arrangement, and the assistant can reason across both in one conversation.

Frequently asked questions

Is a native connector worse than an email MCP server?

No, and on a Gmail or Microsoft 365 mailbox it is usually where you should start. It is free with a subscription you already pay for, it needs no set-up beyond a sign-in, and for searching, summarising and drafting it does the job. This page exists for the cases it does not cover, which are mostly about which mailbox you have and what you want done to it.

Can Claude connect to a mailbox that is not Gmail or Microsoft 365?

Not with a native connector. Anthropic publishes connectors for Google Workspace and for Microsoft 365, and the Microsoft one states in writing that personal Microsoft accounts such as outlook.com and hotmail.com addresses cannot be used. A custom remote MCP server is the documented route to anything else, which is what this product is.

Can ChatGPT move or file my email?

For your own mailbox, OpenAI publishes no message write actions at all in the Outlook app capability list. It does document marking read and unread and moving messages for shared and delegated mailboxes. The Gmail app holds a scope that would authorise labelling, archiving and trashing, but no product page states that any of it is exposed.

Does Microsoft Copilot send email?

Not according to any page we could find. It acts on the mailbox extensively, including flag, archive, delete, move and mark read, and Microsoft describes the drafting flow as ending with the human pressing Send. That is a deliberate design position rather than an oversight: Microsoft says the intent is to give you a chance to review the generated text rather than fully automating it.

Does Gemini file or send mail in Gmail?

It summarises, searches, drafts and suggests replies. Every description of it stops at the draft, so no send. Delete and archive were announced in May 2025 as generally available next quarter and today survive only inside a US-only, top-tier Agent Mode with per-action approval.

Does reading an email through a native connector mark it as read?

No vendor says. That is the single most surprising finding of the reading behind this page: across five products and every page read on 30 August 2026, nobody documents what an ordinary read does to the seen flag. We can tell you what ours does, because we tested it against a real mailbox: reading never sets it.

Can I use both?

Yes, and plenty of people should. Use the native connector for the mailbox it was built for and an MCP server for the one it cannot reach. They are separate tools in the same client, so an assistant can hold your work Microsoft 365 mailbox through Anthropic's connector and your own domain's mailbox through this one at the same time.

What happens to Gmail fetching mail from my other accounts?

Google is withdrawing it. Its own support page gives January 2027 for the removal of Send-as for third-party accounts, Gmailify, and POP fetching, and says you can no longer add or sync a third-party email account in Gmail on the web. If your arrangement for reaching a non-Google mailbox has been to pull it into Gmail, that route is closing.

Sources

Every capability claim above comes from one of these, read on 30 August 2026. Where a vendor contradicts itself, both pages are listed.

• Anthropic: use Google Workspace connectors The Gmail connector's capabilities and stated limits.
• Anthropic: Microsoft 365 connector security guide The published tool list, the attribution header, and the attachment refusal.
• Anthropic: set up the Microsoft 365 connector Entra tenant requirement, and the read-only sentence above the write permissions.
• Anthropic: Claude for Outlook The quoted passage on Mail.Send, and the move and flag operations.
• OpenAI: Outlook email and calendar apps in ChatGPT The capability list, the shared-mailbox actions and the scopes.
• Google: Gmail API scopes What gmail.modify authorises, which is what ChatGPT's Gmail app holds.
• Microsoft: triage email with Copilot in Outlook The quoted passage, and the full list of mailbox actions.
• Microsoft: Copilot requirements Primary Exchange Online mailboxes only.
• Google: Gemini in Gmail What Gemini offers in Gmail, which stops at the draft.