From Required

ERR-P01-MAIL-2002 - From Required

Summary

POST /mails could not resolve a From address for the outbound message.

When this is raised

• The request omits from, and the router has no default From address to fall back to (defaultFromAddr is unset or empty), so the resolved from.mail is missing.
• In normal operation apps/mail injects a default of ${accountId}@<MAIL_DOMAIN>, so this fires only when that default was not set - e.g. a misconfigured MAIL_DOMAIN or a caller path that bypasses the default-From middleware.
• The body has already passed the sendBody schema (ERR-P01-MAIL-2001); this is the next check, specific to sender resolution.

What to do

• Include an explicit from object with a valid mail field in the request body.
• If you expected the server to default the From address, report it to the operator - MAIL_DOMAIN or the default-From middleware is likely misconfigured.
• No message is sent when this fires; fix the From and resend.

Server-side cause

• Raised by: packages/mail/src/router/index.ts - the POST /mails handler, after schema validation: if (!from?.mail) throw MAIL.fromRequired('from address is required').
• Guard: from is body.from falling back to { mail: defaultFromAddr }; when neither yields a mail, the guard throws.

Example response

{
  "type":      "https://citizenry.id/errors/ERR-P01-MAIL-2002",
  "title":     "Bad Request",
  "status":    400,
  "code":      "ERR-P01-MAIL-2002",
  "message":   "from address is required",
  "method":    "POST",
  "instance":  "/mails",
  "request_url": "https://mail.citizenry.id/mails",
  "timestamp": "2026-05-17T07:00:00.000Z"
}

Related codes

• ERR-P01-MAIL-2001 - the body-shape validation that runs immediately before this From-resolution check.

Changelog

• 0.1.0 - introduced.