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.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Microsoft Exchange Server - Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft.
Event Hunt - Startups and Tech Events Curated By Locals
Cyrus IMAP - The Cyrus IMAP server differs from other IMAP server implementations in that it is generally...
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets