Adding a textbox to email sent to outlook

Hi, 
I have a situation where i need to add a textbox inside a email, i added a html textbox in the email. 
If i open the mail in the web browser it is working fine but when i open the mail in outlook it come like "[ ]" 

i need to make this text box editable so that i can add some values to the textbox 

thank you 

varun