454: temporary 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.
- Standard
- Provider
- Temporary (4xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 454
- Provider
- Standard SMTP codes
- Temporary or permanent
- TemporaryThe sending server keeps the message and tries again later.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
454 Temporary authentication failure
What it means
A 454 has two standard uses. RFC 4954 defines 454 4.7.0 for an authentication that failed because of a temporary server problem, and tells clients not to ask the user for another password but to report a server failure. RFC 3207 uses 454 when STARTTLS is not available for a temporary reason. In both cases the credentials and the message are fine, and an attempt later usually goes through. If it lasts, the provider may have an outage, and its status page is the next place to look.
Common causes
- The server's authentication service is down or slow to answer.
- TLS is temporarily unavailable on the server, for example during a certificate change.
How to fix it
- 01Wait and retry; there is no need to change the password because of this reply.
- 02Check the provider's status page for an outage.
- 03If TLS is unavailable and the message is sensitive, wait instead of sending it unencrypted.
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.
- 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.
- 421Service not available.The receiving server is closing the connection and will not take mail right now. The reply is temporary, so the sending server keeps the message and tries again later.
454 at other providers
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