sendmail - Sending mail without smtp server and credentials in asp.net -

I have a contact form in an asp.net website that has the following fields:

< Li> Name
1. Contact Number
2. Email Address
3. Topic
4. Message

   Now whenever a user fills the form and submits it, then I want to receive mail in my inbox with the user's mail as "in".

   Now that I do not know which server user will use and its credentials, how can I send my email address and "to" mail as "from". I know that is quite possible,

   Once you click Hello and send it, it tells you the name of the sender and the name and email of the email and the receiver and this mailer matches the field Sends emails with

   The SMTP client uses a mail message to send email. View links from property of mail message, this is an example of code