List of the Top 3 On-Prem Mail Servers in 2025

Discover reliable, enterprise-grade email, calendar, and collaboration solutions that fit your budget. Kerio Connect presents a wide array of features for communication and teamwork, eliminating the complexities and high expenses typically linked to other services. It offers an integrated experience that combines email with shared calendars, scheduling tools, contact management, tasks, notes, shared and public folders, along with instant messaging capabilities. Users can easily sync their emails to their favorite mobile devices via Microsoft ActiveSync. The Instant Messaging functionality supports XMPP, making it compatible with various third-party chat and IM applications across both desktop and mobile platforms. Setting up Kerio Connect is a breeze, taking only 10 minutes, after which users can begin working almost immediately. This solution can be implemented on-site or through cloud environments hosted by partners, catering to users on Mac, Windows, or Linux systems. Additionally, it ensures full support for Outlook on both Windows and Mac, along with compatibility for numerous other IMAP or POP-compliant email clients, providing flexibility and smooth integration for every user. Embrace a collaborative experience that is straightforward and efficient, allowing your team to focus on what truly matters.

SmarterMail stands out as the perfect alternative to Microsoft Exchange. It uniquely provides native support for essential protocols like MAPI, EWS, and EAS, making it the only business email server available that does so without requiring extra software or plugins for Microsoft Outlook and various other desktop and mobile clients. Furthermore, it comes with all the capabilities of Exchange but at a significantly reduced price. Notably, it also includes features such as audio and video group chat, along with Online Meetings for effective team collaboration, all at no additional cost. This solution is crafted to meet the functional demands of businesses while ensuring secure and dependable access to both professional and personal communications. Ultimately, SmarterMail presents a comprehensive solution that enhances productivity without compromising on security or ease of use.

KumoMTA is a robust and adaptable sending platform designed for high-performance needs, now offered under an Open Source license, catering to high-volume email users seeking an alternative to PowerMTA, Momentum, or conventional Open Source MTAs. This platform provides a versatile solution that can effectively meet the demands of modern email sending.