Zimbra
Zimbra is a client/server to manage mails and calendar; it has the style of Yahoo Mail and Gmail style with a good speed for loading. To make an interface so fast they have optimized like Gmail using AJAX language (Javascript + XML) that stores parts of the content in the client uses.
Advantages
- According to companies that have already migrated to Zimbra, it allows a cost saving of at least 50% compared to MS Exchange or IBM Lotus or Roundcube
- The connector for MS Outlook allows a native synchronization to the Zimbra server. Thanks to the powerful, easy and intuitive interface, Zimbra users feel very comfortable working with the product.
For the Administrator
- Low cost in system management
- Native storage system
- Hierarchical (HSM / ILP)
- Support for Multi-Domain with administration from a single node
- Restoration of a single mailbox per user, from the console
- Online transfer of mailboxes between servers (and backups)
- Integrated high availability solution
- Management interface based on AJAX
- Performance graphics dashboards
- Console command interface
- SOAP integration for administration tasks
- Server and hosting consolidation
- One copy of the email and attachments per server, instead of one email per user
- Significant reduction in CPU usage - Multi-level caching and system optimization
- Compatibility with existing infrastructures
- Web services - API for bidirectional integration with CRM, ERP, etc.
- Customers - Outlook, Mobile, IMAP, POP, iCalendar, RSS, etc.
- Directory - Active Directory Integration/LDAP Messaging Server - Co-existence and migration tools Security
- Web security model - Single sign-on, TLS/SSL, no need to use VPN
- Secure opening of attachments
- SpamAssassin and ClamAV included
- Compatible with existing anti-spam/anti-virus services
For the user
- Free choice of the client
- Browsers - Zimbra Ajax client
- Clients for PC - Outlook (Online, Offline, Cache Mode), Apple Mail and iCal, Eudora, Evolution, Thunderbird / Sunbird, RSS, etc. Mobile phones - Devices
- Wireless "wireless synchronization": Blackberry, Palm, Nokia, Motorola, Good, PocketPC, etc.
- Perfect organization of the mailboxes Advanced and powerful search system (including the attached messages)
- Saved the most common searches
- Viewing emails by conversation
- Mail filters
- Team calendar
- Free/busy meeting management
- Multiple calendars per user
- Share and delegate calendars
- Subscription to external calendars with .ics format
- Integration of email with other applications, via drag and drop
- Intranet - ERP, CRM, Support, Finance, HR, VoIP phone, etc.
- Internet Google/Yahoo Maps, Skype, Travel, Package Tracking, etc.
- Efficient text comprehension system in emails
- View / Create appointments in the calendar, just by hovering over a word or date within the email
- Create / Edit contacts, just move the mouse over the contact within the email
- A quick view of the web page, by hovering the mouse over the contact within the email
- From any computer, at any time Powerful Web interface with AJAX technology Security without VPN
- Secure option to open attachments Modern RSS/ATOM collaboration system news
iRedMail
iRedMail is the application that every system administrator should have at hand without hesitation; is a robust and complete platform to manage mail systems that support all in one, that is:
- SMTP server
- Authentication
- POP3 / IMAP server
- Anti-Spam (RBL)
- Anti-virus (ClamAV)
- MySQL support
- Virtual Domains (virtual domains)
- Webmail
- Full administration via Web
Advantages:
- It is an open source project ( GPL v2 )
- Your binary packages are compatible with the i386 and x86_64 architectures
- Works on non-virtualized and virtualized systems such as VMWare , VirtualBox, Xen, and OpenVZ .
- Works on RedHat/CentOS 5.5 , Debian , FreeBSD , openSUSE and Ubuntu
So, you knew advantages of Zimbra and Iredmail you will know which one is the best for your use.
Hope that helped.