Is 553 5.7.1 permanent or temporary?

553 5.7.1 is a permanent (5.x.x) failure — the server will not accept the message as-is, and retrying without changing anything won't help. You need to fix the underlying cause.

Is this my problem or the recipient's?

It depends on the cause — you're sending as an address you're not authorized to use is the most common. Work through the causes below to find which applies to you.

How do I check my sending setup?

Run a free EmailHealth check on your domain — it verifies SPF, DKIM, DMARC, blacklist status, and more in a couple of seconds, which covers the most common causes of delivery failures.

553 5.7.1 — Sender address rejected / not owned

553 5.7.1 is a permanent SMTP reply meaning sender address rejected / not owned. 5.7.1 with a 553 points at the sender, not the recipient: the address you're sending as is not permitted (often a relay or "sender not owned" rejection).

What 553 5.7.1 means

5.7.1 with a 553 points at the sender, not the recipient: the address you're sending as is not permitted (often a relay or "sender not owned" rejection).

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This is a 5.x.x permanent failure — the message will keep bouncing until you fix the cause. Retrying the same message unchanged won't help.

Common causes

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You're sending as an address you're not authorized to use

Most common

The SMTP server only lets you send from addresses you own/authenticate as, and your From address isn't one of them.

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Relay access denied for that sender

Common

The server won't relay mail with your envelope-from to external recipients without authentication.

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SPF/DMARC at the receiver rejects the spoofed-looking From

Common

Some receivers return 553 5.7.1 when your From domain's DMARC policy rejects unauthenticated mail.

How to fix 553 5.7.1

1
Send only from addresses you're authorized to use
Make sure your From and envelope sender match an account/domain you're authenticated for on the sending server.
2
Authenticate before sending (no open relay)
If you're relaying through a server, log in with valid SMTP credentials so it permits your sender address.
3
Align your domain's SPF and DMARC
If receivers reject your From domain, confirm SPF/DKIM/DMARC pass and align — run a free EmailHealth check.

Confirm your domain is set up correctly

Most delivery failures — permanent or temporary — trace back to authentication or reputation. Run a free EmailHealth check to confirm SPF, DKIM, DMARC, blacklist status, and TLS are all healthy for your sending domain. If you send in volume, free daily monitoring will alert you before a small issue becomes a flood of bounces.

Sender address rejected / not owned