4.7.0 Temporary authentication or policy failure

The receiving server is delaying the message for a policy reason, such as unproven sender reputation, greylisting, or a rate limit. Gmail’s “unusual rate of unsolicited mail” deferral uses this code.

4.7.0 Temporary authentication or policy failure

Temporary: it may work if you retry

Usual causes

A new sending domain or address that the server does not know yet.
Sending faster than the server allows, so it is asking you to slow down.
Greylisting.

What to do

Wait and let the mail system retry. Greylisting and early rate limits clear.
Slow down on a new domain, and increase volume gradually over days.
Check your SPF, DKIM and DMARC.

Usually the fault of: sender.

Common questions.

What does 4.7.0 mean?

Will retrying fix 4.7.0?

Often yes. It is a temporary failure, and mail systems retry for you. If it keeps failing for days, look at the causes listed above.

How do I fix 4.7.0?

Wait and let the mail system retry. Greylisting and early rate limits clear. Slow down on a new domain, and increase volume gradually over days. Check your SPF, DKIM and DMARC.

Other codes: 5.1.1 · 5.1.2 · 5.1.3 · 5.1.6 · 5.2.1 · 5.2.2 · 5.2.3 · 5.3.4 · Decode a whole bounce message

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