553 5.7.1 Sender address rejected: not owned by user Email / SMTP Origin: Network Last updated 4 Nov 2026

SMTP: 553 5.7.1 <noreply@example.com>: Sender address rejected: not owned by user user@example.com

The SMTP server only lets an authenticated user send as addresses they own, and the From/envelope sender does not match the login.

Exact message you may see Sender address rejected: not owned by user553 5.7.1 Sender address rejectednot owned by user553 Sender address rejected: not logged in553 5.1.8 Domain of sender address does not exist
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Seen on: SMTP Linux

Meaning

Servers enforce reject_sender_login_mismatch (Postfix) or equivalent so users cannot spoof others. Use the same address you log in with, or add the alias to that account. Gmail does the same: you must add "Send mail as" aliases and verify them.

Common causes

  • MAIL FROM differs from the authenticated user
  • Missing alias or "send as" permission
  • Application using a generic noreply@ address with a personal account
  • Postfix smtpd_sender_login_maps does not include the address

⚡ Quick fix

  1. Send from the address you authenticate with
  2. Add the address as an alias or "Send mail as" identity
  3. Postfix: map the alias in smtpd_sender_login_maps

Detailed fix by platform

Postfix

  1. smtpd_sender_restrictions = reject_sender_login_mismatch and smtpd_sender_login_maps = hash:/etc/postfix/sender_login with noreply@example.com user@example.com; then postmap and reload

How to diagnose

  1. From — Matches the login?
  2. Alias — Registered?
  3. Rule — Server sender restrictions?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: Network. Errors that are often confused with or caused by this one (click to open):

421 4.7.0 Try again later (rate limited) — SMTP: 421 4.7.0 Our system has detected an unusual rate of unsolicited mail originating from your IP address. Mail sent from your IP address has been temporarily rate limited (Email / SMTP)421 4.7.0 Try again l…450 4.7.1 Greylisted, please try again later — SMTP: 450 4.7.1 <user@example.com>: Recipient address rejected: Greylisted, see http://postgrey.schweikert.ch/help/example.com.html (Email / SMTP)450 4.7.1 Greylisted,…451 4.3.0 Local error in processing — SMTP: 451 4.3.0 Error: queue file write error / 451 Requested action aborted: local error in processing (Email / SMTP)451 4.3.0 Local error…452 4.2.2 Mailbox full / over quota — SMTP: 452 4.2.2 The email account that you tried to reach is over quota (Email / SMTP)452 4.2.2 Mailbox ful…535 5.7.8 Username and Password not accepted — SMTP: 535-5.7.8 Username and Password not accepted. Learn more at https://support.google.com/mail/?p=BadCredentials (Email / SMTP)535 5.7.8 Username an…550 5.7.1 — 550 5.7.1 Relaying denied / Message rejected as spam / Unauthenticated email not accepted (Email / SMTP)550 5.7.1550 5.7.26 — 550 5.7.26 This mail has been blocked because the sender is unauthenticated (SPF/DKIM/DMARC) (Email / SMTP)550 5.7.26Laravel: Expected response code 250 but got 550 — Laravel: Expected response code "250" but got code "550", with message "550 5.7.1 Relaying denied" (Email / SMTP)Laravel: Expected res…553 5.7.1…

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