530 5.7.0: authentication required
Your client tried to send through a Google SMTP server that needs a signed-in account, without signing in first.
- Gmail
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 530 5.7.0
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
530 5.7.0 Authentication required.
What it means
Google's SMTP submission service, smtp.gmail.com, accepts mail only from authenticated accounts. The client sent MAIL FROM, or another command, without completing AUTH, so Gmail answered with this reply. Google links it to its help for people who cannot sign in to their Google Account. The usual cause is a client set to send without authentication, or one that carries on to MAIL FROM after its sign-in failed. Devices that cannot sign in can use the Workspace SMTP relay instead, which can recognize them by IP address.
Common causes
- SMTP authentication is turned off in the client's settings.
- The client sends MAIL FROM even though its sign-in failed.
- The client was pointed at smtp.gmail.com when it was meant to use a relay that does not need sign-in.
How to fix it
- 01Turn on SMTP authentication and enter the account's credentials.
- 02Connect on port 587 with STARTTLS or on port 465 with TLS, then sign in.
- 03If the device cannot sign in to Google, use an app password or the Workspace SMTP relay instead.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- Gmail SMTP errors and codes (Google Workspace Admin Help)knowledge.workspace.google.com
Related codes
- 530 5.7.0STARTTLS required first.Gmail requires your client to switch the connection to TLS with STARTTLS before it signs in or sends mail, and your client did not.
- 534 5.7.9App password required.The account uses 2-Step Verification, so Google will not accept its normal password from your mail client and asks for an app password instead.
- 530Authentication required.The server requires the client to log in, or to start TLS, before it accepts this command, which usually means before it accepts any mail.
- 5.7.0Security or policy refusal, unspecified.The message or session was refused for a security or policy reason that the server did not describe more precisely, or chose not to reveal.
5.7.0 at other providers
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