Standard SMTP codes · permanent error
530: authentication 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.
- Standard
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 530
- Provider
- Standard SMTP codes
- 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 Authentication required
What it means
RFC 4954 defines 530 5.7.0 as the reply to any command other than AUTH, EHLO, HELO, NOOP, RSET or QUIT when policy requires authentication and the client has not logged in. RFC 3207 uses 530 for a server that requires STARTTLS first. It is how a submission server tells a mail client or an application that its outgoing settings are incomplete. Nothing is sent until the client logs in, or starts TLS, and tries again.
Common causes
- The mail client's outgoing server settings have authentication switched off.
- An application sending through a provider's SMTP server without credentials.
- A server that requires STARTTLS before any other command.
How to fix it
- 01Turn on authentication for the outgoing server in the client and enter the account credentials.
- 02Enable STARTTLS or implicit TLS on the port your provider documents.
- 03Check that the application's SMTP settings include a username and a password or token.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
Related codes
- 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.
- 535Authentication credentials invalid.The server rejected the login because the username, password or token is wrong or not sufficient for this account, so no mail is sent.
- 503Bad sequence of commands.The client sent a command at the wrong point in the conversation, for example message data before any recipient was accepted, or mail before logging in.
- 454Temporary authentication or TLS failure.A login or a TLS handshake could not be completed because of a temporary problem on the server; the client should try again later without changing anything.
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