Based on our record, Postfix 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.
Read the documentation on postfix.org and/or buy one of the many available Postfix books (it really helps to understand the Postfix philosophy). Source: about 3 years ago
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.
iRedMail - A fully fledged, free email server solution, an open source project (GPL v2).
HEY - Email at its best, new from Basecamp.
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.
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
Exim - Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet.