Mailwarm - The email warm-up tool.
Thunder Mail - Cheap and simple transactional emails API with Amazon SES
Warmbox.ai - Warm up your cold email inbox, and never land in spam anymore!
MailClark - The Slack bot for external communications
Warmup Inbox - Warmup Inbox is a tool that automates the process of warming up your email inboxes, raising your sender reputation and inbox health automatically.
PigeonBot - Send emails via Slack with the /email command