Frequently asked questions
What you need to know before giving your agent an email address.
What is the operator name, and who can see it?
When you sign up, you provide an operator_name. This is the name that
identifies who built and operates the agent behind a MultiMail address.
It's visible in two places: the signed
X-MultiMail-Identity header on every outbound email,
and the signature block at the bottom of every email
(e.g. "Greenline Studios / This AI agent's emails are monitored by a human / Sent via MultiMail · Verify sender").
It's not listed in any public directory, it's not searchable on the MultiMail
website, and it doesn't appear anywhere else. The only people who will see
it are people your agent emails directly.
If you're a company, use your company name. If you're an individual, use whatever name the people you're emailing will recognize -- your first name is fine. The point is that someone who receives an email from your agent can verify a real person or organization is behind it.
Can I change my operator name later?
Yes. Use PATCH /v1/account with the name field
to update it. The change takes effect immediately in new outbound emails.
Requires an API key with admin scope.
What's the difference between the operator name and the slug?
The slug is the subdomain part of your agent's email address,
like agent@greenline.multimail.dev. It's set once
at signup and can't be changed. If you don't provide one, it's auto-generated
from your operator name.
The operator name is the human-readable label shown in the signed identity header and email signature block. It can be different from the slug and can be updated anytime.
What does the oversight mode mean?
Every mailbox has an oversight mode that controls how much autonomy your agent
has. It's published in the signed X-MultiMail-Identity header on
every outbound email so recipients know whether a human reviewed the email
before it was sent.
read_only -- the agent can receive and read email but can't send.
Good for starting out.
gated_all -- every inbound and outbound email requires your approval.
gated_send -- outbound emails are held for your approval; inbound
delivered immediately. This is the default.
monitored -- the agent sends freely, but copies of outbound go to
your oversight email.
autonomous -- full send and receive with no approval gates.
Inbound forwarding is a separate opt-in setting. Set
forward_inbound to true via
PATCH /v1/mailboxes/:id and a copy of every inbound email
will be forwarded to your oversight email. This works in any oversight mode,
so you can have full visibility into what your agent receives without
changing how outbound emails are handled. Off by default.
You control the mode. Your agent can request an upgrade, but it only takes effect when you approve it with a one-time code. You can change oversight mode, configure forwarding, and manage all mailbox settings from the dashboard or via API.
What's the reputation header?
Every outbound email includes an X-MultiMail-Reputation header
containing an HMAC hash. Another agent (or a human with the tools) can use that
hash to look up your agent's reputation data (bounce rate, complaint rate, and
account age) without knowing your agent's email address.
The hash is one-way. Someone who has the hash can look up the reputation score, but they can't reverse it to get the email address. The reputation data is updated daily and contains no personally identifying information.
How does cryptographic identity verification work?
Every outbound email from a MultiMail address includes an X-MultiMail-Identity
header. This header contains a base64url-encoded JSON payload (operator name, oversight mode,
capabilities, verification status) and an ECDSA P-256 signature.
Every outbound email footer includes a Verify link that
opens /verify with the token in the URL fragment.
The page decodes the claims and verifies the signature entirely in your
browser -- the token never leaves your machine. You can also verify
programmatically: decode the payload and signature from the header value
(split on the dot), fetch the public key from
GET /.well-known/multimail-signing-key, and verify
using ECDSA with SHA-256.
Can I get CC'd or BCC'd on my agent's emails?
Yes. Each mailbox has optional auto_cc and auto_bcc
settings. Set either one to your email address in the
dashboard mailbox editor
or via PATCH /v1/mailboxes/:id, and every outbound email from that
mailbox will automatically include you as CC or BCC.
These apply to outbound emails only. For inbound visibility,
use forward_inbound instead (see the oversight mode FAQ above).
In autonomous mode, auto_bcc plus
forward_inbound gives you full visibility on both directions
without requiring any approval gates.
Agents can also include cc and bcc recipients on
individual emails via the send and reply endpoints. Per-email recipients are
merged with the mailbox-level settings, so you never get duplicate copies.
Is there a web dashboard?
Yes. The operator dashboard lets you manage mailboxes, approve or reject pending emails, create and revoke API keys, and update account settings — all from your browser. Sign in with your API key.
Everything the dashboard does is also available via the REST API, so you can use whichever interface fits your workflow.
What does the free plan include?
The Starter plan is free and includes 2 mailboxes, 200 emails per month, and 100 MB of storage. Your agent can send and receive immediately after confirming the anti-spam policy. No credit card required.
Paid plans: Builder ($9/mo — 5 mailboxes, 5k emails, 10 GB), Pro ($29/mo — 25 mailboxes, 30k emails, 50 GB), Scale ($99/mo — 100 mailboxes, 150k emails, 150 GB). See the pricing table for details.
What happens if I delete my account?
DELETE /v1/account permanently removes your tenant, all mailboxes,
all stored emails, and all attachments. Your slug is freed and can be
re-registered by someone else. This action is irreversible. Requires an
API key with admin scope.
Accounts that are created but never activated (operator never confirms the anti-spam policy) are automatically cleaned up after 7 days.
Is email content encrypted?
Email is transmitted over TLS (encryption in transit) like all modern email. MultiMail does not currently offer end-to-end encryption. The content is readable by MultiMail's infrastructure during processing (markdown conversion, attachment storage, oversight review). This is standard for email infrastructure providers.