Have you checked your MX records? I don't see one for your domain:
>
> I just installed POP-before-relay package and now none of the
> domains on my
> server can receive email. When mail is sent, the sender receives a
> delivery failure message (see below). What files does the
> POP-before-relay
> script change? What is causing every domain to refuse accepting mail?
> Please help.
>
> ----- The following addresses had permanent fatal errors -----
> <tmorrison@xxxxxxxxxxxxxxxxxx>
>
> ----- Transcript of session follows -----
> <tmorrison@xxxxxxxxxxxxxxxxxx>... Deferred: Connection refused by
> bpcinteractive.com.
> Message could not be delivered for 3 days
> Message will be deleted from queue
>