OneBar - AI-powered Q&A knowledge base for Slack teams
PopcornNotify - Send simple emails and text messages from one API
Whatis - Manage & organize your team's knowledge straight from Slack
MailerSend - Better transactional emails for teams.
Tettra - Tettra is a company wiki that helps teams manage and share organizational knowledge.
PigeonBot - Send emails via Slack with the /email command