NullBox is described as 'email privacy service that protects the privacy of your inbox with disposable email addresses. NullBox acts as a protective shield for your inbox' and is an app in the Security & Privacy category. There are more than 50 alternatives to NullBox for a variety of platforms, including Online / Web-based, Google Chrome, Firefox, SaaS and Windows. The best alternative is AnonAddy, which is both free and Open Source. Other great apps like NullBox are MailDrop (Free, Open Source), Spamgourmet (Free, Open Source), 10 Minute Mail (Free) and Burner Mail (Freemium).
MailDrop is a free throwaway e-mail address. It's temporary. It's transient. It's disposable. It's meant for those times when you don't want to give out your real address. Just give someone any e-mail address in the maildrop.
Spamgourmet provides disposable, optionally self destructing, email addresses that get created automatically the first time they are used, forward messages, and then automatically expire after number of specified messages received.
Guerrilla Mail gives you a disposable email address. You can give your email address to whomever you don't trust. You can read the email using Guerrilla Mail, click on any confirmation link, and even reply.
Bouncr allows you to hide your permanent email address behind an '@boun.cr' address. You then share it however and with whomever you wish. Anytime you're receiving unwanted emails, simply cancel your Bouncr address and it's gone.
Inboxkitten is an open-source disposable email service that you can freely deploy adopt on your own! Use any inbox to avoid spam Use inboxkitten when you don't want to get spammed by revealing your real email address. Email Auto-Deletes