Best On-Premises Email Clients of 2025

Combine social collaboration, messaging, and business applications into a unified workspace with HCL Notes. This email client software provides teams with essential tools such as email, calendar, and contact management, while also integrating various collaboration resources and HCL Domino business applications. With its enhanced user experience and improvements to critical mail functionalities, HCL Notes evolves your routine email usage into a central operational hub, becoming increasingly vital for your team's productivity. By integrating social collaboration, messaging, and business applications into one cohesive workspace, Notes enhances daily workflow significantly. Currently, leading logistics firms, influential banks, and fashionable brands depend on Notes to streamline their operations and improve efficiency in their everyday tasks. The versatility of HCL Notes makes it an indispensable tool for organizations seeking to optimize their collaborative efforts and communication strategies.

SmarterMail is the ideal Microsoft Exchange alternative. First, it's the only business email server on the market that offers native support for the protocols that power Exchange: MAPI, EWS, and EAS. It does this without the need for any additional software or plug-ins for Microsoft Outlook or other clients -- desktop and mobile! Best of all, it offers all of the features of Exchange, but at a FRACTION of the cost. In addition, features like audio and video group chat, and Online Meetings for team meetings and group collaboration are included at no extra charge. It's designed to provide the functionality businesses need, without sacrificing secure, reliable access to business, and personal, communication.

OpenText GroupWise delivers a robust suite of communication and coordination capabilities that help organizations manage email, calendars, tasks, and contacts in one unified interface. Its intuitive, customizable design enables IT teams to tailor the experience to user needs while maintaining full administrative control and compliance readiness. By supporting role-based rules, proxies, and workflow features, it reduces the time required to manage communication across large or distributed environments. GroupWise also enhances collaboration with intelligent meeting scheduling, shared address books, and flexible environment integration, including compatibility with Zoom and Active Directory. Its built-in protection—ranging from multifactor authentication to secure messaging gateways—helps defend against emerging threats like spam, phishing, and DDoS attacks. Users benefit from seamless mobility through synchronized desktop-to-mobile experiences on Windows, Mac, Linux, and modern browsers. Disaster recovery features ensure rapid restoration, helping IT maintain high availability even during outages. Overall, the platform empowers organizations to communicate more efficiently while safeguarding critical business information.