This error:

Fra: Mail Delivery System [mailto:MAILER-DAEMON@zorro.cirque.dk
<MAILER-DAEMON@zorro.cirque.dk>]
Sendt: 20. juli 2012 09:58
Til:


.....

.....

 The mail system

<xxx@trifork.com <xxx@trifork.com>>: host mxfilter01.netic.dk
<http://mxfilter01.netic.dk>[77.243.50.207 <tel:%5B77.243.50.207>] said:
550 #5.7.1
Your access to submit messages to this e-mail system has been
rejected. (in
reply to RCPT TO command)

Is often caused because the sending mail server (in this case zorro.cirque / 77.234.175.128) has a poor score on Senderbase