Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
TempMail - Temp Mail is the provider of fake and temporary email ID.
Keybase Chat - End-to-end encrypted chat built into Keybase
10 Minute Mail - Temporary disposable e-mail service to beat spam. Avoid spam with a free secure e-mail address.
Crypho - End-to-end-encrypted messaging and file sharing
Mailinator - Any Inbox. Any Time.