Just think that probably the customers won't like to get their PC's unprotected, if that is the case then you should think on changing the way you handle the e-mail in your application.
Take a look here: http://www.naughter.com/freenetwork.html
] Where PJ Naughter made a great job in e-mail handling.
Take a look at the first link CPJNSMTPConnection and if you read carefully the instructions you will be able to get it working without much hassle it is easy after all.
Good luck! :rose: