Gmail and Google Workspace · permanent error
554 5.7.0: too many unauthenticated commands
Gmail closed the session because your client sent too many commands without signing in, on a service that needs authentication.
- Gmail
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 554 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
554 5.7.0 Too many unauthenticated commands.
What it means
On the servers where Gmail expects a client to sign in before sending, a client that keeps sending commands without authenticating is eventually cut off with this reply. It usually comes from a mail client or device that is set up for smtp.gmail.com without SMTP authentication, or one that issues MAIL FROM and other commands before AUTH. The fix is to configure SMTP authentication with valid credentials over an encrypted connection.
Common causes
- A client set up for smtp.gmail.com without SMTP authentication.
- A client that issues commands such as MAIL FROM before AUTH.
- A client looping on failed commands without signing in.
How to fix it
- 01Turn on SMTP authentication in the client and enter valid credentials.
- 02Connect over TLS, on port 587 with STARTTLS or on port 465, before signing in.
- 03Check the session log for the commands sent before AUTH, and fix their order.
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 5.7.0Authentication required.Your client tried to send through a Google SMTP server that needs a signed-in account, without signing in first.
- 554Transaction failed.The server permanently refused the transaction, often after receiving the message data or straight away when the connection opened.
- 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
All 108 Gmail codesEvery code in the wikiPaste your own bounce