Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
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.
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.
Warmbox.ai - Warm up your cold email inbox, and never land in spam anymore!
Mailpile - Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
MailReach.co - The #1 email warming service to improve your deliverability by generating realistic and meaningful engagement to your emails. Easy-to-use solution to help you land in the main inbox instead of the spam folder.