To configure Email OTP verification,

1. In your form builder, navigate to Settings > Spam Control.
   

2. Click OTP Verification and click Configure Now.
   
   
   
   

3. In the pop-up, select Email.
   
   
   

4. Select the From address. If you wish to display a From Name while sending emails, click Add From Name.
   

   

   Note : If you select notifications@zohoforms.com to be the From address, then the form admin's email address will be set as From Name by default and this cannot be modified.

5. You can change the default email Subject and the OTP message to be sent in the email as required. You can also include the link to the OTP Verification page where the respondent is required to enter the received OTP in the email message by clicking the   icon. If the respondent has entered the OTP, then the link in the email will redirect to the form and not to the OTP Verification page.
   
6. OTP expiration time:  Set the time within which a respondent is required to enter the OTP verification code.
7. Number of OTP resend requests allowed:  You can set the number of times a respondent can opt to resend the OTP code to their email.
   
8. Map OTP-verified Email to a form field:  You can pre-fill an email field in the form with the verified email address by selecting the required form field from the dropdown.
   

   Note :
   

   • The following properties configured for the selected Email field  will be applied to the email address entered by the respondent for verification:
     

   • Domain Validation
     

   • Character Limit
     

   • No Duplicates Validation
     

   • Email input confirmation 
     

   • If you want to restrict your respondent from editing the pre-filled Email field in the live form, select the Disable Field option under Email field Properties.   
     

9. To add an extra layer of security and prevent spam entries, you can include a Zoho Forms CAPTCHA under Spam Control and evaluate if it is a human or a bot that is filling your form. Learn more  
10. Click Save.