# Email signing (/docs/sign/email-signing)

Signers with `delivery: "email"` (the default) get an email with a signing link when it's their
turn. Possession of that link identifies them (`authentication: "email_link"` in the audit trail).

- **Invitations** go out within seconds of the request being sent. With
  `signing_order: "sequential"`, each signer is invited once everyone before them has signed.
- **Reminders** go out every `reminder_interval_days` (on the request, defaulting to your Sign
  settings'), up to three, to signers who haven't signed. Ask for one now with
  `coss.sign.requests.remind(id)` (at most once an hour per signer).
- **Expiry:** a request past its `expires_at` becomes `expired` (`sign_request.expired`), and its
  links stop working.
- **Signed copies:** once the request is completed and sealed, each email signer gets the signed PDF
  (attached up to 10 MB, always with a download link).

```ts twoslash
import { Coss } from "coss";
const coss = new Coss();
// ---cut---
await coss.sign.settings.update({
  email_from: "contracts@acme.com",
  reminder_interval_days: 3,
});
```

## Who it comes from [#who-it-comes-from]

With `email_from` set to an address on one of your [verified domains](/docs/email/domains), signing
emails come from it, through your environment like any email you send (your suppression list and
history apply). Without it they come from coss.com as "Acme via coss.com", and leave out the
request's `message`.

Every email has a fresh link that works for 30 days (or until the request expires); open and click
tracking is off and coss.com doesn't keep the email's body.