GuideUpdated October 17, 2026

Use multiple email accounts with Claude or ChatGPT

Claude's built-in Gmail connector works with the Google account you connected, and users report that a second account only works after disconnecting the first. ChatGPT handles several Gmail accounts only where its Gmail app offers that for your account. Addresses at other providers, such as a domain hosted by your web host, are not part of either connector. To give an AI agent all your mail, you first bring the addresses together in one place, and then connect the agent to that place.

Command Mail is our product. This guide compares the options, their limits and the setup steps, then walks through the setup with Command Mail.

Updated: Fact-checked: About 10 min readAs Markdown

Contents
  1. What you will have at the end
  2. Where native connectors fall short
  3. Four ways to give an agent several addresses
  4. What you need
  5. Steps
  6. Check that it worked
  7. Common problems
  8. Next steps
  9. Frequently asked questions
  10. Sources

01What you will have at the end

One connector in Claude or ChatGPT gives the agent every address you own: say a personal Gmail address, a Microsoft 365 work address and billing@ on your own domain. You can ask "What arrived across all my inboxes since yesterday?" or "Only show mail sent to my work address", and the agent answers from a single source.

You also decide, mailbox by mailbox, how much the agent may change on its own, from read-only to sorting by itself. Permission to send is granted separately.

02Where native connectors fall short

Anthropic states that Claude can only access the Gmail, Calendar and Drive data of the Google account you connected; the help page does not state a maximum number of accounts.[1] An open user issue in the Claude Code repository, filed in March 2026, reports that only one Gmail account can be connected and that connecting a second requires disconnecting the first. The request is to connect several accounts and target each one by address.[4] Check whether your Claude interface now offers another account.

Adding your own connector as a workaround is tight on the free plan, because Anthropic limits Free users to one custom connector.[2]

ChatGPT is less clear cut. OpenAI writes that some apps support multiple connected accounts, depending on the app and your account; where this is available, the app's page under Settings → Plugins shows Connected accounts and an option to connect another account.[6] An issue in the Codex repository from June 2026 reports the opposite experience with Gmail, a single active account, and asks for named accounts so replies come from the address that received the mail.[8] Check what your own ChatGPT offers.

Even with two Gmail accounts connected, Outlook, your own domain and other providers remain separate apps or are not available at all. ChatGPT lets you choose when it asks before an action, from Always ask to Allow all actions.[5] Where the app supports it, you can set this per connected account, so a second account in the same app can have a different setting.[15] Command Mail adds its own autonomy level per mailbox, which applies the same way to every agent you connect.

03Four ways to give an agent several addresses

The options differ mainly in who holds your mail and how precisely you control what the agent does.

OptionDifferent providersEffortMain limitation
Switch the connected accountnolowone account at a time
Forward everything into one Gmail accountyesmediumall mail sits together in the chosen Google account
Run your own MCP serverdepends on the projecthighyou host it and register your own OAuth client
Use Command Mail as a shared inboxyesmediumworks on forwarded copies, no sync back

Switch accounts. Disconnect one Gmail account and connect the other when you need it. It is free and fine if the second account matters rarely. A question across all inboxes is not possible this way.

Forward into one Gmail account. Send your other addresses to a main Gmail account and connect only that one to Claude or ChatGPT. This is the least expensive route to a combined view. The connector's own limits stay in place; in Claude, for example, attachments show metadata only.[1] All forwarded mail then sits together in the Google account you chose. For work mail, your organization's rules have to allow that.

Run your own MCP server. Open source projects such as google_workspace_mcp connect Gmail and other Google services to an agent. According to its README you create your own Google Cloud project and OAuth client and host the server yourself.[11] That suits developers who want full control and accept the maintenance.

Use an inbox built for agents. Command Mail gives each address its own private intake, receives mail by forwarding, and exposes all mailboxes through one connector.[13] You approve scopes when you connect, and you set an autonomy level per mailbox.[12] The trade-off is that Command Mail works with copies. Archiving or deleting there leaves the original mailbox as it was.

04What you need

  • A Command Mail account. The free plan includes one mailbox, the last 90 days, reading, search, sorting and drafts, with no sending; extra mailboxes pause but keep receiving. Several addresses need Pro, which covers up to ten mailboxes with full history and sending. On 2026-10-17 Pro costs €19 per month for the first 100 paying Pro accounts and €29 after that, and a 7-day trial costs €1.[12]
  • Access to the settings of each existing mailbox so you can turn on forwarding.
  • An agent that supports remote MCP. Claude supports custom and directory connectors on every plan; on Team and Enterprise, an owner adds the connector for the organization first.[2] In ChatGPT, Command Mail's public directory listing is still under review, so you add it yourself as a custom MCP server. According to OpenAI you no longer need to turn on Developer Mode for this. Full MCP support, including write actions, is currently available to ChatGPT Business, Enterprise and Edu on the web. On Business only admins and owners can add custom MCP servers; on Enterprise and Edu, admins can grant that right to members. Pro users can connect custom servers with read and fetch permissions only.[7]

05Steps

Connect the addresses first, then forward, then add the agent. That way the inbox already holds mail the first time the agent looks.

Step 1: Create an account

  1. Go to commandmail.app and choose Start free. You can sign up with Google, Apple or email.[12]
  2. Signing in with Google shares only your name, email address, profile picture link and account ID. It gives Command Mail no access to Gmail, Drive or Calendar.[13]

Step 2: Connect each address

  1. During first setup, enter your first address in the Connect a mailbox step, for example your Gmail address.
  2. Command Mail returns a private intake address for it. Copy it, then continue to your inbox.
  3. For every further address, open Settings → Connections. In the Addresses section, enter the address under Connect a mailbox and click Add.
  4. The new address appears in the list with its own intake address. Copy it for forwarding.

If you prefer the terminal, the CLI does the same, once per address, and needs Node.js 18 or later:[13]

curl -fsSL https://commandmail.app/install.sh | sh
commandmail login
commandmail mailboxes connect billing@yourcompany.com

Step 3: Turn on forwarding at each provider

Gmail: Settings → See all settings → Forwarding and POP/IMAP (or just Forwarding) → Add a forwarding address. Paste the intake address and click Next → Proceed → OK. Gmail sends a verification link to that address; it arrives in Command Mail, where you open it. Back in Gmail, refresh the page, select Forward a copy of incoming mail to, choose Keep Gmail's copy in the Inbox, and click Save Changes.[9]

Outlook.com: Settings → Mail → Forwarding and IMAP → Enable forwarding, enter the intake address, Save. In new Outlook and Microsoft 365 the path is Settings → Mail → Forwarding, and you can tick Keep a copy of forwarded messages.[10]

A domain at your web host: Add a forward to the intake address in your host's control panel, and keep a copy in the old mailbox if it should stay complete.

Step 4: Connect your agent

Claude (web and desktop): Open Command Mail in the Claude directory and choose Connect. Or go to Customize → Connectors → Add → Custom → Web and enter https://commandmail.app/mcp.[14][3]

ChatGPT (on the web, with an eligible plan and permission):[7]

  1. Open Plugins, select the plus button and choose Add custom MCP server.
  2. Enter a name such as Command Mail and, optionally, a description.
  3. Under Connection, enter https://commandmail.app/mcp and set up OAuth sign-in.
  4. Read the risk warning, tick I understand and want to continue, and select Create as a plugin. Review the tools it found.
  5. Install the plugin, sign in to Command Mail, and start a new conversation. Type @ and select the plugin.

Claude Code:[12]

claude mcp add --transport http commandmail https://commandmail.app/mcp

Step 5: Choose permissions

After you sign in, Command Mail shows an authorization page. Start with mail:read, which covers reading, searching and sorting within the mailbox's autonomy level, and mail:draft, which saves drafts and never sends. mail:send-approved sends exactly the draft revision you approved. mail:send lets the agent send on its own within a daily limit; leave it off until you have a clear use for it.[12]

Step 6: Set autonomy for each mailbox

Open Automation & rules and, under How much may your agent do?, pick a level for each mailbox. New mailboxes start at auto: the agent carries out sorting actions without asking each time. Supported sorting actions such as archiving, spam, moving to the trash and filing into folders are logged and can be undone.[14] Sent emails and permanent deletion cannot be undone, and label changes are not covered by undo either. To watch first, choose suggest: supported sorting actions such as archiving, spam and trash then wait as suggestions. With read, Command Mail refuses these sorting actions from the agent.[13] Neither level limits sending: an agent with mail:send can send from any configured sender address, even if its mailbox is set to read. An agent holding both mail:read and mail:send can currently also delete mail permanently through the REST API under suggest. Do not give a sorting or reading agent mail:send.

06Check that it worked

Send a test message from another account to each address. Within a few minutes each one should appear in the matching mailbox in Command Mail.

Then ask the agent: "Which mailboxes can you see in Command Mail, and what are you allowed to do?" It calls capabilities first, and the answer lists the owner, your granted scopes and every mailbox with its autonomy level.[14] On the free plan, a second mailbox is listed too, marked as paused.

A second check: "Summarize what arrived since yesterday, grouped by address." A summary that covers every address means you are done.

07Common problems

Gmail's verification message never shows up. Make sure the address is connected in Command Mail and that you pasted the right intake address, since Gmail sends the link to exactly that address.[9]

Spam is missing. Google forwards all new messages except spam.[9]

An address is missing from the agent's answer. First check whether it is listed under Settings → Connections → Addresses.

An address is marked as paused. Only one mailbox is active on the free plan. Others keep receiving, but their mail stays hidden until you move to Pro.[12]

Older mail is missing. Forwarding only covers new mail. Bring older messages over once from an MBOX or EML export, for example with commandmail import export.mbox --mailbox billing@yourcompany.com. An import is not an ongoing sync.[13]

Nothing changes in the original mailbox. That is by design: Command Mail works on copies and writes nothing back.

Claude ignores the connector. Turn it on for the conversation with the plus button → Connectors.[3]

ChatGPT offers no write actions. On plans without full MCP support, OpenAI allows read and fetch only for custom servers.[7]

The agent says it cannot send. The free plan does not send. On Pro the agent also needs mail:send-approved or mail:send and a sender address you have set up.[12]

08Next steps

If Gmail and Claude are your main pair, Connect Gmail to Claude compares the built-in connector with Command Mail step by step. Every connection option, scope and limit for agents is on For agents; forwarding, the CLI and autonomy are covered in the documentation.

You can start Command Mail free with one address and connect your agent in a few minutes.

Frequently asked questions

Can Claude connect to two Gmail accounts at the same time?

Anthropic describes access to the Google account you connected and documents no multi-account option. An open user issue from March 2026 reports that connecting a second account means disconnecting the first. Check whether your Claude interface offers another account; if not, combine your addresses in one mailbox first.

Does ChatGPT support more than one Gmail account?

OpenAI says some apps support multiple connected accounts and that this depends on the app and your account. Open Settings → Plugins → Gmail. If you see Connected accounts with an option to connect another account, you can add a second one.

What is the cheapest way to see all my mail in one place for Claude?

Forward your other addresses into one Gmail account and connect only that account to Claude. It costs nothing extra, but business and personal mail then share one Google account, and the connector's limits still apply.

Does Command Mail change my original Gmail or Outlook mailbox?

No. It receives copies through forwarding. Archiving, sorting or deleting in Command Mail does not touch the original mailbox, and importing old mail is a one-time copy with no ongoing sync.

How many addresses does Command Mail support?

Free covers one mailbox and the last 90 days; extra mailboxes pause but keep receiving. Pro covers up to ten mailboxes with full history and sending, at €19 per month for the first 100 paying Pro accounts and €29 after that (checked 2026-10-17).

Sources

  1. Anthropic: Use Google Workspace connectors support.claude.com, accessed
  2. Anthropic: Get started with custom connectors using remote MCP support.claude.com, accessed
  3. Anthropic: Use connectors to extend Claude's capabilities support.claude.com, accessed
  4. GitHub issue anthropics/claude-code #36024: Support multiple Gmail accounts in MCP integration github.com, accessed
  5. OpenAI: Connected apps in ChatGPT help.openai.com, accessed
  6. OpenAI: Connecting and managing app accounts in ChatGPT help.openai.com, accessed
  7. OpenAI: Connecting custom MCP servers in ChatGPT help.openai.com, accessed
  8. GitHub issue openai/codex #30418: Gmail connector should support multiple named accounts github.com, accessed
  9. Google: Automatically forward Gmail messages to another account support.google.com, accessed
  10. Microsoft: Turn automatic forwarding on or off in Outlook support.microsoft.com, accessed
  11. GitHub: google_workspace_mcp (README) github.com, accessed
  12. Command Mail: llms.txt with plans, scopes and connection options commandmail.app, accessed
  13. Command Mail: Documentation commandmail.app, accessed
  14. Command Mail: For agents commandmail.app, accessed
  15. OpenAI: Managing app permissions in ChatGPT help.openai.com, accessed
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