Postigo
Sign in Try for free
530

Authentication Required

The mail server requires authentication before accepting mail. You must log in to send.

The server asks to retry later. Usually resolved automatically.

SMTP error 530 means the server requires you to authenticate:

  • SMTP authentication (AUTH) is mandatory
  • Credentials were not provided
  • Server requires login before relaying mail
  • TLS/SSL connection may be required first

Common Causes

  • no_accounts
    No Credentials Provided

    Your mail client or server isn't sending authentication credentials.

  • settings
    Auth Not Configured

    SMTP authentication is not enabled in your email client settings.

  • security
    TLS Required First

    The server requires a secure connection (STARTTLS) before accepting authentication.

    • Service not available

    1. Enable SMTP Authentication

    In your email client settings, enable 'My outgoing server requires authentication' or similar option.

    2. Enter Credentials

    Provide your username (usually email address) and password for the SMTP server.

    3. Use Secure Connection

    Enable TLS/SSL for the SMTP connection. Try port 587 with STARTTLS or 465 with SSL.

    4. Check App Passwords

    If using 2FA, generate an app-specific password for your email client.

    Mailbox unavailable 
    530 5.7.0 Authentication required
530 5.7.1 Client was not authenticated
530 Must issue a STARTTLS command first

    Local error in processing

    535 Authentication Failed 503 Bad Sequence of Commands 550 Mailbox Not Found 504 Parameter Not Implemented

    Insufficient storage

    Server unable to process

    Try for free