Encrypted Emails with PDF Attachment

I need to send encrypted emails using C# without using any third party component. This is pretty much working as long as I do not need attchments on the email but as soon as I add attchments, I face the same problem as described on [login to view URL] Please not that this is is standard email encryption using Digital IDs so you will require Public Key (cer files) and Private Key (pfx files) to send out encrypted emails. ## Deliverables My function structure is static void SendEncryptedEmail( string SigningCertPath, string EncryptingCertPath, string strPassword, MailMessage theEmail) Which pretty much explains itself. theEmail is the MailMessage which has a few PDF Attchments so a loop will be required here.