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SMTP error code · Gmail / Google Workspace

Gmail 550 5.7.1: the IP you're using to send email is not authorized

550 5.7.1 Permanent failure (5xx): the message bounced
By iBlockSpam Team Checked against sources 3 sources How we check our content
What it means

Gmail refused the connection because the IP address your mail came from is in a range its ISP doesn't authorize to send mail directly, typically a home or dynamic broadband address.

What the bounce says
550 5.7.1 The IP you're using to send email is not authorized to send email directly to our servers. Use the SMTP relay at your service provider instead.

Gmail's text for this 550 5.7.1, as listed in Google's SMTP errors reference (the published line also points to a help article).

What 550 5.7.1 means

Google says Gmail refuses mail from IP addresses that aren't authorized to send mail, to prevent spam, and that the decision is made by the ISP that provides the IP address. The list typically contains consumer ranges for dial-up, DSL and other broadband access. In other words, Gmail isn't judging your message or your domain; it's refusing direct delivery from that kind of connection.

This usually hits small offices running their own mail server on an ordinary internet line, NAS boxes and home servers sending alerts, and scripts on a laptop sending straight to Gmail's MX. Google lists the fixes: use the SMTP relay your ISP provides, get a business-class or static IP that the ISP authorizes, or send through your own domain's mail servers, either by allowing relay from your IP or by submitting mail with authentication (a mail submission agent).

Google also says it can't allowlist IP addresses or make exceptions, so asking Gmail to unblock the address won't help. Because the reply is 550, the message bounced and won't be retried.

Likely causes

  • Your server sends directly to Gmail from a home or dynamic broadband IP address.
  • The ISP lists your IP range as not authorized to send mail.
  • A device or script delivers straight to Gmail's MX instead of through your mail provider.

How to fix it

If you sent the message

  1. Send through your email provider or ISP's SMTP relay with authentication on port 587, instead of delivering directly.
  2. If you must run your own server, ask your ISP for a business or static IP that's authorized for mail, with a matching PTR record.
  3. Don't ask Google for an exception: Google says it can't allowlist IP addresses.

If you're the recipient or their admin

  1. No action needed at Gmail: the sender has to change how the mail leaves their network.
Reverse DNS (PTR) Lookup Blacklist Checker Email Health Check

Frequently asked questions

Can Google unblock my IP for the 'not authorized to send email directly' error?

No. Google says it's unable to allowlist IP addresses or make exceptions. The ISP decides whether the range is authorized, so the fix is to send through a relay or get an authorized business IP.

Why can I send to other providers but not Gmail from my home server?

Receivers use different policies. Gmail refuses direct delivery from IP ranges the ISP marks as not authorized for mail, which typically covers dial-up, DSL and other consumer broadband.

Sources

  1. Gmail SMTP errors and codes (Google Workspace Admin Help)
  2. 'The IP you're using to send email is not authorized...' (Gmail Help)
  3. RFC 6409: Message Submission for Mail

Provider messages are quoted as the provider publishes them. Servers can change their wording, so the bounce you received may differ slightly.

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