IDNS is a company that is notorious for sending out mailers in envelopes to domain owners. They get your information from the public WHOIS registry and then mail you a letter notifying you that your domain may be expiring soon (sometimes it doesn’t expire for several more months). They urge you to sign the mailer and include payment to renew your domain.
Once you renew your domain with IDNS, they now have the right to transfer your domain from your current registrar into their domain registrar. So, for example, if you originally registered your domain at GoDaddy, you will no longer be able to manage your domain from within the GoDaddy customer portal. It will be transferred to the IDNS registrar and you will have to manage it there.
This is what their solicitation looks like… PLEASE BEWARE!! Quik123 does NOT recommend proceeding with the solicitation. Just throw it in the trash.