It is thrown when the server refuses a command, for example when the sender
domain is not authorized or a recipient is rejected. Inspect SMTPError.code
or SMTPError.enhancedCode to make a delivery decision; the message
is intended for humans and is not stable.
An SMTP reply that rejected a submission.
It is thrown when the server refuses a command, for example when the sender domain is not authorized or a recipient is rejected. Inspect SMTPError.code or SMTPError.enhancedCode to make a delivery decision; the
messageis intended for humans and is not stable.