I have an issue with mails coming from this forum: Our Emailserver does reject them with following error:

I can problaby convince my company to make an exception-rule for qcu.be, but i think it would be nicer if it used a fully-qualified hostname. I can imagine that other mailservers behave so too (in order to protect its users from typical spam-patterns).
As far as I understand the problem seems to be the "helo=". Our Mailserver probably expects something like "qcu.be".