Is a collaboration suite (messaging and groupware). Is a collaboration suite (messaging and groupware). It is designed to run on open source operating systems such as Linux or BSD. In order to modernize the Citadel platform for the Internet, the Citadel/UX developers added functionality such as shared calendars, instant messaging, and built-in implementations of Internet protocols such as SMTP, IMAP, Sieve, POP3, GroupDAV and XMPP. All protocols offer OpenSSL encryption for additional security.Users of Citadel/UX systems also have available to them a web-based user interface which employs Ajax style functionality to allow application-like interaction with the system. More Info »Citadel uses the Berkeley DB database for all of its data stores, including the message base.
Find Top 10
Citadel
Alternatives
| # | Image | App Name | Features | Platforms | Price | Website Link |
| 1 |  |
Zimbra Collaboration Suite | Web | Self-Hosted Linux |
Freemium | Website |
| 2 |  |
iMail | Self-Hosted Windows |
Commercial | Website | |
| 3 |  |
Zarafa |
Web Discontinued |
Mac Windows Linux |
Commercial | Website |
| 4 |  |
Kolab Community | Web | Self-Hosted Linux |
Freemium | Website |
| 5 |  |
hMail Server | Windows | Free | Website | |
| 6 |  |
OX Open-Xchange | Web | Self-Hosted Linux |
Free | Website |
| 7 |  |
Atmail Email Server | Web | Linux | Commercial | Website |
| 8 |  |
MDaemon Messaging Server | Windows | Commercial | Website | |
| 9 |  |
Sanwhole Exchange | Windows | Commercial | Website | |
| 10 |  |
Microsoft Exchange Server | Web | Windows | Commercial | Website |