I’m trying to send email to the company, but got the following error message.
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of
its recipients. This is a permanent error. The following address(es)
SMTP error from remote server for RCPT TO command, host: mxbiz1.qq.com (184.108.40.206) reason: 550 Sender frequency limited.
I’m just wondering that is the mail server down?