Expanding Communication Alternatives

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft.

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.

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.

Visit website paid $19.5 / Monthly (Pro)

Is a collaboration suite (messaging and groupware).

MailEnable is a Windows based mail server and email server program that is packed with the state of the features and functions like antivirus and spam filtering system, webmail management system, cardDAV, CalDAV and much more.

OBM is a free messaging and collaboration platform useful for just a couple to many thousands of users with strong support for mobile devices.

Third party hosting for Microsoft Exchange services.

hMailServer is a free e-mail server for Microsoft Windows.

Fast, safe, heavy mail solution.

Save time and scale faster with accessible, secure, and reliable cloud email services. A proven multitenant email solution for telcos and service providers.

freemium $1.3 / Monthly (Per mailbox)

Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.

SquirrelMail is a standards-based webmail package written in PHP.

open-source

Google's encompassing suite of cloud-based business apps.

OpenChange aims to provide a portable Open Source implementation of Microsoft Exchange Server and...