Cryptgeon - Securely share self-destructing notes
Mailinator - Any Inbox. Any Time.
BURN.link - Send secure, encrypted, self-destructing messages
TempMail.altmails - Disposable temporary email addresses
Burner Note - Burner Note is a free, ad-free and open sourced service for sending secure text based notes that are completely erased from existence once they've been read.
Harakirimail - Harakirimail is a free disposable email service. Just send email to anythingyouwant@harakirimail.