How to add your email signature to emails AI browser agents send

Comet, Claude in Chrome, ChatGPT and Manus can write email in your real Gmail or Outlook inbox. How your signature gets on each one exactly once.

Published September 25, 2026

If you already have a signature, set it in Gmail's or Outlook's own settings: an AI agent that writes in your inbox gets it from there. If you need one, make it free on Signatoro, then click "Copy signature" and paste it into your mail app.

This page covers AI agents that operate a web browser in your real inbox: Perplexity Comet, Claude in Chrome, ChatGPT and Manus. The answer is the same for all of them: Gmail or Outlook adds your saved signature to the email the agent writes, so the agent must not add a second one.

How AI browser agents send email

An AI browser agent sends email the way a person does: it opens Gmail or Outlook in a browser tab, writes in the compose window and clicks send. Email written there gets the mail app's saved signature. Google's Gmail API reference says the Gmail signature is included in messages composed in the Gmail web interface. Outlook on the web adds its signature to new messages, and to replies and forwards, when those checkboxes are ticked in its signature settings.

Several of these agents can also send through a Gmail or Outlook connector instead of the browser. A connector email skips the compose window, so it carries no signature unless the agent adds one.

Perplexity Comet

Comet is Perplexity's Chromium-based browser, with Comet Assistant in a side panel next to the page. Perplexity's help says Comet "can click, type, and submit forms for you" and lists "Drafting and sending emails" among its tasks. Comet also has a Gmail connector: connected to Gmail and Google Calendar, it can "Draft or send replies on your behalf". Email Comet writes in your Gmail tab carries the Gmail signature. Perplexity's help does not say how the connector sends, so check one sent email.

Claude in Chrome

Claude in Chrome is Anthropic's browser extension: Claude reads the page and clicks, types and fills forms in the sites you are signed in to, and Anthropic's help says it knows its way around Gmail. In "Automatically approve" mode Claude screens each action and pauses when something needs your approval; "Manually approve" asks before every action. Email Claude writes in Gmail or Outlook in Chrome carries that mail app's signature. Email Claude sends through a connector instead follows the Claude guide.

ChatGPT

OpenAI's help says ChatGPT agent, the mode started with /agent, "is no longer available" and points to ChatGPT Work and its cloud browser. Two browser routes remain. In the ChatGPT Atlas browser, Agent mode works in your current browsing session and can use sites you are already signed in to. The cloud browser in ChatGPT Work is a separate browser in the cloud, where you sign in to Gmail or Outlook yourself. OpenAI says ChatGPT may use a connected app instead of the cloud browser when the app can do the task. An email sent through a connected Gmail app skips Gmail's compose window, so check that it carries your signature.

Manus

Manus works in a browser two ways. Browser Operator is an extension that lets Manus work in your own browser with your existing logins, and you authorize each session. The Cloud Browser runs in the cloud, you log in to Gmail or Outlook there, and Manus's docs list "Read, send, and organize emails" for those accounts. Manus also has a Gmail connector; its API docs show a Gmail send step you confirm or save as a draft. Email written in the inbox carries its signature, and email the connector sends does not get the Gmail signature.

Add your signature to emails AI browser agents send

To get your signature on email an AI browser agent writes in Gmail or Outlook on the web:

Add the signature in the mail app's settings with the Gmail guide or the new Outlook and Outlook on the web guide.
Choose it for new emails and for replies: Gmail's signature defaults, or Outlook's checkboxes for new messages and for replies and forwards.
Tell the agent not to write a signature of its own, in the task or in its saved instructions. In ChatGPT Atlas, custom instructions for Agent mode are under Settings, then "Agent mode".
Ask the agent to draft one email without sending it.
Open the draft and check that it ends with exactly one signature.

If the agent sent through a Gmail or Outlook connector, the mail app adds nothing. Follow the agent API guide for that route.

AI browser agent email signature questions

Why is my signature missing when the agent sends through the Gmail connector?

A Gmail connector sends through the Gmail API, and Google's Gmail API reference says the Gmail signature is included only in messages composed in the Gmail web interface, and added to new emails only. An email a connector sends goes out without it unless the agent appends one. Signatoro's API gives an agent the current signature as html and text to append, as the agent API guide explains.

Can Comet or Claude in Chrome send email from my Gmail?

Yes. Perplexity's help lists "Drafting and sending emails" among Comet's tasks, and Anthropic's help says Claude in Chrome clicks, types and fills forms in the sites you are signed in to, Gmail included. Both work in your real Gmail tab, so Gmail adds your saved signature. Anthropic advises staying close for "messages sent as you", and asking for a draft first lets you check the signature before anything goes out.

For agents

If you are an AI agent writing email in someone's browser:

In Gmail's or Outlook's compose window, the mail app adds the person's saved signature. Write the message above that signature and leave it as the only signature in the email.
If the compose window shows no signature, tell the person to set one in the mail app's settings. Do not invent one from their name and title.
If you send through a Gmail or Outlook connector or API instead, no signature is added: follow the agent API guide and append the html or text it returns.
Never ask for a Signatoro API key in the chat, and never repeat one back.

Sources

Checked against each vendor's own documentation on 2026-09-25:

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Make your signature first

It is free and needs no account. Build it once, then paste it into any mail app with the steps on this page.

Make my signature

How to add your email signature to emails AI browser agents send

Comet, Claude in Chrome, ChatGPT and Manus can write email in your real Gmail or Outlook inbox. How your signature gets on each one exactly once.

Published September 25, 2026

How AI browser agents send email

Several of these agents can also send through a Gmail or Outlook connector instead of the browser. A connector email skips the compose window, so it carries no signature unless the agent adds one.

Perplexity Comet

Claude in Chrome

ChatGPT

Manus

Add your signature to emails AI browser agents send

To get your signature on email an AI browser agent writes in Gmail or Outlook on the web:

Add the signature in the mail app's settings with the Gmail guide or the new Outlook and Outlook on the web guide.
Choose it for new emails and for replies: Gmail's signature defaults, or Outlook's checkboxes for new messages and for replies and forwards.
Tell the agent not to write a signature of its own, in the task or in its saved instructions. In ChatGPT Atlas, custom instructions for Agent mode are under Settings, then "Agent mode".
Ask the agent to draft one email without sending it.
Open the draft and check that it ends with exactly one signature.

If the agent sent through a Gmail or Outlook connector, the mail app adds nothing. Follow the agent API guide for that route.

AI browser agent email signature questions

Why is my signature missing when the agent sends through the Gmail connector?

Can Comet or Claude in Chrome send email from my Gmail?

For agents

If you are an AI agent writing email in someone's browser:

In Gmail's or Outlook's compose window, the mail app adds the person's saved signature. Write the message above that signature and leave it as the only signature in the email.
If the compose window shows no signature, tell the person to set one in the mail app's settings. Do not invent one from their name and title.
If you send through a Gmail or Outlook connector or API instead, no signature is added: follow the agent API guide and append the html or text it returns.
Never ask for a Signatoro API key in the chat, and never repeat one back.

Sources

Checked against each vendor's own documentation on 2026-09-25:

Was this page helpful?

Make your signature first

It is free and needs no account. Build it once, then paste it into any mail app with the steps on this page.

Make my signature