message rejected due to spam or virus

[#1]

I'm trying to send a set of log messages to an email address and I'm getting:

Final-Recipient: rfc822; abuse@worldstream.nl
Original-Recipient: rfc822;abuse@worldstream.nl
Action: failed
Status: 5.0.0
Remote-MTA: dns; relay.plus.net
Diagnostic-Code: smtp; 552 dJqt1u0020mutzo01Jqvm6 message rejected due to spam
    or virus. If you believe this is in error please login to your portal or
    contact your ISP support team.

Is this PN's email server rejecting it or the target host?

[#2]

OK apparently this is Plusnet stopping me reporting things.. the IP address and domains in the log are obviously tripping Plusnet's spam filters.....