Hi Cam,
It's "technically" not valid because your incoming mail server is mail.samreesor.com which then connects to worldsecuresystems.com which is what BC (secure) runs on.
There's nothing wrong with this message as you know (and trust hopefully) the server you're connecting too. Mail's just informing you that your server name and the originating host name are different, which is what it says at the top of that box. If it's something else that you weren't familiar will, you'd be suspicious.
Click on Trust underneath and select the option to "Always trust this certificate." This will stop the message from continually showing up.
