Microsoft Exchange Server is recommended for medium to large organizations that require a secure, customizable, and robust email solution, especially those already using other Microsoft products. It is ideal for businesses that prefer on-premises solutions with full control over their data and infrastructure, or for those in regulated industries with specific compliance requirements.
Based on our record, Rainloop seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Have a local mail server be part of your development environment, along with a frontend like SquirrelMail or RainLoop. - Source: dev.to / 7 months ago
Roundcube - Web-based IMAP email client
Zimbra - Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.
Mailpile - Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
iRedMail - A fully fledged, free email server solution, an open source project (GPL v2).
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
DistroWatch - 9 hours ago - It does include a proprietary software set optimized for business users, students, researchers and developers." A list of features and further details can be found in the company's release announcement.