Message bouncing back
I am getting message bouncing back when sending message through salesinbox
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) failed:
email@emai****.com
host outbound.mailspamprotection.com [61.15.20.222]
SMTP error from remote mail server after end of data:
550 Maximum line length exceeded (see RFC 5322 2.1.1).
Looking forward to your answers.
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) failed:
email@emai****.com
host outbound.mailspamprotection.com [61.15.20.222]
SMTP error from remote mail server after end of data:
550 Maximum line length exceeded (see RFC 5322 2.1.1).
Looking forward to your answers.