Give an AI agent its own email signature when it sends unsupervised, from a dedicated address, under an agent name. Let it use your signature when it drafts emails that you read and send yourself. Once a team runs several agents, say a sales agent, a support agent and a scheduling agent, each one needs a separate signature: its name, a line saying it is an AI, the person or company it acts for, and a way to reach a human. Keep that signature outside the prompt, so one agent cannot pick up another's.
| Setup | Whose signature | Example sign-off |
|---|---|---|
| AI drafts, you read and send from your mailbox | Yours | "Sam Lee, Head of Sales, Northwind Supply" |
| An agent sends from your mailbox without your review | Yours, plus a disclosure line | "Sent by Sam Lee's AI assistant" above your signature |
| An agent has its own address and works for one person | The agent's own | "Ada, AI assistant to Sam Lee, Northwind Supply" |
| An agent has its own address and works for the company | The agent's own | "Sage, AI sales assistant, Northwind Supply" |
| Several agents sign as one team | One shared team signature | "Northwind Support Assistant (AI)" |
The people and companies in the examples are fictional.
Why AI agents end up signing as each other
When the model writes the sign-off, the sign-off is only as stable as the model's context. A developer running three agents, each on a separate Google Workspace account, described the failure on the gog CLI issue tracker: the agents "each needed their own server-side signature to prevent prompt-level identity drift ('Sage signed as Ada')." Their workaround was a prompt that reads a sign-off file and pastes it at the end of each email, which they called "reliable but fragile on LLM discipline."
Three things cause most of the drift:
- Shared context. Agents that share memory, files or a thread history see each other's names and sign-offs, and a model reuses what it has just read.
- A sign-off in the prompt. A signature typed into instructions gets paraphrased, shortened or swapped, and goes stale the day someone changes their title.
- One agent talking as its principal. A user in r/AI_Agents wrote of their multi-agent setup that "it will randomly start saying it's me and talking as if it is coming from me. [...] I can't have it pretending to be me."
The fix is to tie each agent's signature to the agent's own credentials. The agent asks for its signature at send time with its own key, gets back one signature, and appends it without rewriting it. The model writes the message; the signature comes from outside the model.
What the EU expects an AI agent to say about itself
This section is general information, not legal advice.
The European Commission's guidelines on Article 50 of the AI Act say AI agents that interact with people while "managing correspondence" must be designed to "disclose both their artificial nature and the person on whose behalf they are acting". The same paragraph extends this to "complex multi-agent architectures", where an agent works through other agents that deal with people directly.
Applied to email, that is two facts per agent: it is an AI, and it acts for a named person or company. A shared, anonymous sender such as "The Northwind Team" gives the reader neither. The Commission's own email example puts an "AI label at the top" of the message, so a per-agent signature complements that label; it does the "on whose behalf" half. Our EU AI Act Article 50 guide covers who the duty falls on, and the AI email disclosure guide compares the US, UK and EU.
How to name an AI agent in an email signature
A naming pattern that works across agents:
[Agent name], AI [role] to [person] | [Company] | [how to reach a person]
Ada, AI assistant to Sam Lee | Northwind Supply | sam.lee@northwind.example
Sage, AI sales assistant for Sam Lee, Head of Sales | Northwind Supply | Reply to reach Sam
Nova, AI support assistant | Northwind Supply Support | Reply 'human' to reach our team
Iris, AI scheduling assistant to Priya Shah | Northwind Supply | priya.shah@northwind.example
Rules that keep agent identities clear:
- Put "AI" in the title. "Ada, AI assistant to Sam Lee" tells the reader what Ada is on the first read. A bare first name reads as a person.
- Name the principal. Every agent works for someone. Name the person for a personal assistant, and the company or team for a shared one.
- Give one agent one name. Reuse the same agent name across every email and channel, and never reuse it for a second agent.
- Keep real employees' names for real employees. An agent can work for Sam Lee; it signs as itself, with Sam named as the person it works for.
- Give a route to a human. A named person's address, or "reply 'human'", tells the reader what to do when the agent cannot help.
The AI disclosure statement examples post has lines for the top of the message that pair with these signatures, and Should your AI assistant sign emails as you? covers when signing as yourself is the right call.
One mailbox per agent makes one signature per agent possible
An agent can carry a signature of its own once it has an address. Agent mailboxes are now a product category:
- AgentMail gives an agent an inbox through an API.
- Nylas Agent Accounts give an agent a hosted mailbox on your own domain.
- A Squad teammate comes with an inbox.
- A Google Workspace or Microsoft 365 account for each agent, sending through the Gmail API or Microsoft Graph, as the developer above did.
An agent that sends from a person's mailbox signs as that person's assistant at most, since the From line already names the person. For agents that send on their own, a separate address per agent keeps the From line, the signature and the replies pointing at the same identity.
How to give each AI agent its own signature in Signatoro
Signatoro treats an agent the way it treats a person: each agent is its own person in your company, with its own signature to fetch.
- Agentic sending and API fetch. Each agent fetches its current signature when it sends, with
get_signatureover Signatoro's MCP server or with the agent's own key on the signature API, and appends it. The key decides which signature comes back, so Sage's key always returns Sage's signature. - A name, title and contact per agent. The owner invites the agent's email address as a member, with the agent's name and title, such as "AI assistant to Sam Lee". Each agent keeps a separate name, title, phone, email and extra link.
- Company parts set once. On a Company plan, the owner sets the company name, website, logo, layout, color and font for everyone, people and agents alike. On the larger Company plans, one compliance footnote sits under every signature, and only the owner can change it.
- Updated everywhere at the next send. Change an agent's title or the company logo once, and every agent fetches the new version with its next email.
To set one up: invite the agent's address from your company page, open the invitation from that inbox to join, then generate the agent's API key on its signature page and store it in the agent's secrets. Each agent counts as a person on your plan. The one signature for multiple AI agents page shows how several agent providers share the same company design, and the agent setup guides cover Claude, ChatGPT, n8n, Zapier, Make, Nylas, the Gmail API and Microsoft Graph.
A signature for every agent on your team
Give each agent its own name and title next to your team's signatures, fetched fresh with every email it sends.
Frequently asked questions
Should each AI agent have its own email signature?
Yes, when the agent sends unsupervised from a dedicated address. Its signature should give its name, say it is an AI, name the person or company it works for, and offer a way to reach a person. An agent that only drafts emails you send yourself can use your signature.
Should each AI agent have its own email address?
An agent that sends unsupervised is easier to identify, audit and reply to with a dedicated address. Replies reach the right agent, its sent mail stays in one place, and its From line matches its signature. Agent mailbox services such as AgentMail and Nylas Agent Accounts exist for this.
Can several AI agents share one email signature?
They can when they sign as one team, for example "Northwind Support Assistant (AI)". When each agent writes under its own name, give each its own signature, so a reader can tell which agent wrote which email.
Should an AI agent have a human name?
A name is fine as long as the title says the agent is an AI and names who it works for, as in "Ada, AI assistant to Sam Lee". In the EU, the Commission's guidelines say AI agents should disclose that they are AI and on whose behalf they act.
How do I stop my AI agents from signing as each other?
Take the signature out of the prompt. Give each agent separate credentials and have it fetch its signature at send time, then append it unchanged. A signature fetched with the agent's own key comes back the same every time.
Sources
Checked on 2026-10-07:
- European Commission: Guidelines on the transparency obligations under Article 50 of the AI Act, C(2026) 5054, 20 July 2026, paragraphs 31 and 36
- GitHub, openclaw/gogcli: gmail send: Add --signature flag to append Gmail signature, #180, comment of April 2026
- Reddit r/AI_Agents: post on a multi-agent assistant speaking as its owner