[bitfolk] Email grief - email not being sent?

Hi all, I wish to set up sending email from my vps - and I have been testing php's mail facility. Mail to two of my addresses (@googlemail.com, and @ntlworld.com) work just fine. Three out of three got through - all within 2 or 3 seconds. Mail to my preferred address - this one - is not being delivered, although the call to mail returns true. (three out of three lost). I wish to know why. The server handling my incoming mail, is running on my firewall, with a "dynamic" IP address, and thus the IP is in various black lists. Could this be the reason for the non-delivery? Seems a long-shot to me. Why should bitfolk care? Any other reason I could check out? Regards - and thanks for you input. Ian