Using MS Outlook in .NET

Using Outlook Library 1.0, i've created sending mail, My requirement is like this, I need to to put the mail in outbox folder(client have not yet opened the outlook), once when the user opens the MS Outlook, the Mail from the outbox should be sent. Should i need to set any property for that. And also one more clearification, once i use the Send() method for MailItem, it asks for a popup window "Program is trying to automatically send email on your behalf", is there any way to hide this popup and continue sending the message Pls help me out! Thanks in Advance, Raj