Hi Diceman,
About your problem, emails not getting through. That is common now a days, even legitimate emails get cataloged as spam.
There are two sides to getting past spam filter: server issues and issues with the physical email. When using 3rd party email sending companies there is little to nothing you can do about server issues. But when it comes to emails there is plenty you can do.
First you can have a read at all the things Spam Assassin looks for:
http://spamassassin.apache.org/tests_3_1_x.html
To see how spam stealthy your emails are you can check them here:
An instant one:
http://spamcheck.sitesell.com/
One that takes a few minutes:
http://www.viloria.com/secondthoughts/archives/00000179.html
Kind Regards,
Nicolas Johnson
Gambling Wages
Assistant Affiliate Manager
MSN nicolas_1875 at hotmail dot com