Okay, so what I need to do is to write C# code, to integrate into an existing application.
I will (most likely) be using a Nokia 7230 mobile phone, and I'm willing to use the Nokia PC Connectivity SDK/API, or just AT commands over from C#, whatever works.
The catch here, though, is that I have absolutely no idea where to even start. I would be eternally grateful if someone could give me a step-by-step guide/tutorial on how to go about setting everything up. I've downloaded the newest versions of the PC Connectivity SDK, the PC Connectivity API, the PC Suite, and the Nokia Connectivity Framework.
If it's at all possible for me to test code with an emulator before actually purchasing a phone, that would be fantastic.
Thank you in advance for any help/advice.
GSMComm is a useful C# library for this, it comes with a bunch of samples/tools to mess around with as well.
I get the impression you going to buy a Nokia handset specifically to handle your SMS stuff? If so, you could just buy a GSM Modem (depending on your location) they are cheaper, don't include extraneous features and are not dependent on using manufacturer specific software.
What you are looking for is called an "SMS Gateway". Most of the articles on the internet discuss how to create one using Linux.
I did find this article though, which teaches you how to do it using C#: http://www.ozekisms.com/high-performance-sms-gateway/product-manual/index.php?owpn=315
It looks like you need the Nokia PC Connectivity API (note: Forum Nokia registration required for download):
Developers can use the Content Access API to build PC applications that create, modify, and delete SMS and MMS messages. The API can be used to send and receive SMS and MMS messages.
来源：https://stackoverflow.com/questions/3256665/how-to-send-receive-sms-messages-from-c-sharp-application-using-nokia-mobile-ph