How to use SSL certificates on Android platform within Unity3D?

I am building a utility to check for certain messages in a POP3 account. I am using the POP3 Email Client by Peter Huber since it works with .NET 2.0.

I am developing on Windows. Initially I got the "Invalid certificate received from server" error, but after figuring out how to install the CA certs in the Mono CA store I was successful on the Windows platform (use the mozroots.bat which runs mono.exe and then calls mozroots.exe).

When I build and run on Android the error returns. I have not found a solution to installing certs in a 'mono CA store' on Android and it doesn't seem that TcpClient or SslStream will access the native OS's CA Store.

The exception occurs in this line: ((SslStream)pop3Stream).AuthenticateAsClient(popServer);

Is there a solution for authentication on Android?

Also, I tried playing with the callback for "ServicePointManager.ServerCertificateValidationCallback" but the code never gets called. I have seen many examples that assign (using =) but since this is a listener it should always be adding it to the (possibly preexisting) chain (using +=) right?

Thanks.