problem emailing subscriptions

I am having a problem getting new posts emailed to subscribers to that topic. 

I believe I have email working because the site will send an email from the profile pages, and that seems to work both with various smtp servers and without.

But none of the new postings get mailed to subscribers. I have confirmed that the subscribers are actually subscribed and the radio button for allowing subscriptions is selected.

Is there something I am still missing here?

Thanks

[update]  problem solved - the messages were being sent and just screened by the spam filter, even though the spam filter wasn't filtering those that are sent directly from the profiles page.