Why does Zerodha not allow users to register with Rediffmail email IDs?

Zerodha does not allow users to register with Rediffmail email IDs for the following reasons:

• Increase in cyberattacks targeting Rediff mail accounts. If a client is logging in from a new city or IP address. An email alert is sent to ensure the client is notified of possible breaches in their account.  To learn more, see Why was an email sent alerting about a login from a different city?
• Non-delivery of emails. Emails sent by Zerodha are frequently not delivered to Rediffmail email addresses. Users must go through all the emails from Zerodha since all important communication is sent via e-mail.

If an account is already opened with a Rediffmail email ID, it is advisable to change it. To change the registered email ID, see How to change the registered mobile number or email address with Zerodha?