Email fails when Pop before SMTP

Hello,

My mail server/host as an anti-spam protection requires that an account "checks" their email prior to sending out any messages.  They don't actually require SMTP authentication, but they do require logging into the POP server before sending to an external address.

http://en.wikipedia.org/wiki/POP_before_SMTP

The current NOP builds dont appear to support this.  Any help/suggestions on this?

BTW, Heres the error I get whenever I send email to a reciepient outside of my domain.

Mailbox unavailable. The server response was: ... Relaying Denied. Please check mail before sending.

I confirmed with my hosting provider that the problem was what I described in the previous post

Ive written  the code to make a TCP connection to the POP3 server.  Ive tested it in a console application.  At minimum this code would need to run every 30 minutes from the server NopCommerce is hosted on.  Although It could run before each time an email is sent to ensure sending permission is allowed for the server.  Where would be the best place to insert this code?