If you contact me by e-mail and you don't hear back from me, it is possible that you're also in the spam filter. If your message has an attachment, it might be useful to try again without the attachment.
Of course it's also possible that your message made it to my inbox, and I am trying to find time to reply to you, but I am not always successful at that. Blogging has led to an increase in the amount of e-mail I receive, and a simultaneous decrease in the amount of time I have to reply to it. Polite reminders are appreciated!
But then again, if you are contacting me about a commercial venture, you want to improve my google ranking (it is just fine, thank you), or something like that -- I've already hit the delete key.
Apologies for the spam filter problem. I've tried to resolve this in the past, and it is likely to be a continuing problem.