Loop Email's Shared Inbox makes teamwork on email simple and painless. Share the workload by assigning incoming emails to colleagues, discussing emails with your team via side-chat and have an overview of all client conversations.
Mattermost is an open source, self-hosted Slack-alternative. As an alternative to proprietary SaaS messaging, Mattermost brings all your team communication into one place, making it searchable and accessible anywhere.
Plum Mail is an alternative to email that uses your existing email address. With plum mail, have structured thoughtful conversations and do so much more with your correspondence than traditional email or instant messengers allow