SMTP Error 504 - Command Parameter Not Implemented

info

What This Error Means

SMTP error 504 indicates a valid command with an unsupported parameter:

help

lock
Unsupported Auth Method
The authentication mechanism (PLAIN, LOGIN, CRAM-MD5) isn't supported by the server.
code
Invalid Encoding
The specified encoding parameter isn't recognized or supported.
extension
Extension Parameter
An SMTP extension parameter that the server doesn't support.

check_circle

If related to AUTH, try a different authentication method (PLAIN, LOGIN, or CRAM-MD5).

Use EHLO to check what parameters the server supports before using them.

Configure your mail server to use only standard, widely-supported parameters.

504 5.5.4 Unrecognized authentication type
504 Command parameter not implemented
504 5.7.4 Unrecognized authentication mechanism