If you have a firewall, antivirus or corporate network, all messages to your server will be "vetted" for any signs that they may or may not be a spam email.

When this happens, there are a number of checks that take place, and one of these is to make sure that the mail server that sends you an email had the authority to send that email.

So for example www.bob.com have their hosting with RedStar, and they host their own emails - so their server will assume that the RedStar email server has no right to send emails on behalf of Bob... and it will flag the emails as spam.

This can be fixed by either a) gettting your IT departmentt to resolve the issue, or b) by setting up an SPF record to tell your email server (and everyone elses) that RedStar Creative have the right to send emails on your behalf too.

You can create an SPF record here:
http://old.openspf.org/wizard.html

The IP address of our server is 94.136.45.3, and the hostname is usually ds6003.dedicated.turbodns.co.uk.

Please note: RedStar cannot offer any assistance in cofiguring SPF records.