I read the topic regarding this issue and implemented the "fix" that was instructed there.
But for some reason I am still getting responses like such.
Code:
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:
kalembo@hotmail.com
SMTP error from remote mail server after end of data:
host mx3.hotmail.com [65.55.37.104]: 550 5.7.0 (COL004-MC3F43) Message could not be delivered. Please ensure the message is RFC 5322 compliant.
Not ALL hotmail accounts but for some, that one for example is a personal mail of mine. what else can be the culprit?