通过.Net应用程序发送电子邮件后Outlook RPC服务器不可用

I've just started having a look at interoperability between .Net and Office apps, particularly Outlook. I've managed to get emails to send through Outlook but for some reason the RPC server for outlook shuts down after I've sent an email (if outlook wasn't already running). Here's my code:I've just started having a look at interoperabi