I am developing a bulk mailing application in C#.NET, a windows based application with the object MailMessage and SMTPClient and SMPT login credentials i.e., NetworkCredential.

The application has the following input fields:
1. From Name
2. From email ID
3. SMTP Host
4. SMTP user name
5. Password
6. Subject
7. Message content
8. Recipient List

Application uses this above information to send mails. While sending mails, the user name which is used for Networkcredential is used as from email ID by default even though I have specified different From email ID. How to resolve this issue in the application?

And also how to identify a mail which is sent from this application to multiple recipients at a time is sent or bounced or the mail is opened by the recipient?

Please help on this.