We're sorry to inform you that deleting your account is not possible at all. Apparently, your account will be closed after a year or so of not using it, but no one seems to be able to confirm this.
What you can do is, remove all your personal details from your account, and complain here: http://f4mail.rediff.com/ajaxprism/feedback?output=web - and hope for a reply.
Cancellation/Removal Form (third party service)
Because an account at Rediffmail cannot be deleted, we suggest to make your data useless.
Be logged in on the site, then go to Profile Settings (Or Options, etc.). In all fields with personal data (such as name, address, city), fill in AccountKiller, if possible. If you can only choose from several options, change the value. If possible, use a homepage/URL field or long text field (such as Description) and put this line in it: https://www.accountkiller.com/removal-requested. This may incite webmasters to add an account deletion option.
If you can't find any contact info and still wish to ask something, for example a question about what exactly is deleted, about data retention, etc., you may contact the domain owners using this info.
If you signed up for Rediffmail using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Rediffmail. Click the icon below to find out how.