mpop is a small, fast, and portable POP3 client. Its features include header-based email filtering (filter junk mail before downloading it), delivery to mbox files, maildir folders, or a mail delivery agent, a very fast POP3 implementation, many authentication methods, and good support for TLS/SSL.
getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
stdnoj is a cross-platform C++ class library that includes classes for using portable strings, databases, SMTP, POP, NNTP, arrays, files, directories, logging, email, and sockets. While templates are used, no reliance upon STL or other (traditionally error-prone) technologies has been used, which increases portability between compilers.
Roundup is an issue-tracking system that is simple to use and simple to install. It has command-line, Web, and email interfaces. It manages a number of issues (with flexible properties such as "description", "priority", and so on) and provides the ability to submit new issues, find and edit existing issues, and discuss issues with other participants. The system facilitates communication among the participants by managing discussions and notifying interested parties when issues are edited.
Collaba is a multimedia collaboration and communication server built to provide digital workspaces to virtual educational, corporate, and other communities. It features secure email (Web, POP3/SMTP, crypto, and anti-spam), online forums (Web, RSS, NNTP, and podcast), blogs (Web, RSS, podcast), multimedia chat (text, multimedia panel, etc.), personal and group calendering, address books, bookmarks, an online Web page editor, file services and CMS (Web, WebDAV, FTP, SMB, CIFS, anvi-virus API, and ClamAV support), digital portfolio, dynamic news board, directory access, support for multiple independent communities on one server, Single-Sign-On features (built-in support for LDAP, CAS 2.0, JAAS, SMTP-Auth and more, powerful developer API), full online server management, anti-spam (RBL and filters), anti-virus support, centralized management with LDAP directories, Web publishing of personal, group or general web sites, developer APIs, and much more.
iBeans aims to make integration for Web applications much easier than it is today. It does this by focusing on simplicity and task-based integration and avoids technical jargon and new concepts wherever possible. It offers easy to use integration for doing things like publishing and subscribing to JMS queues and topics, sending and receiving email, polling resources such as databases and ATOM feeds, task scheduling, creating HTTP/Rest services, consuming external services such as Amazon EC2 and S3, Twitter, Flickr, Google, and much more. It proves a Tomcat distribution that drops straight into Tomcat, with no need to mess with your project dependencies, and works with developer tooling for Tomcat or Tcat. It has a very simple API using annotations. This means iBeans can be plugged into your existing Web apps easily. It includes easy unit and mock testing using JUnit. IBeans Central offers a great place to discover and try new iBeans in your applications.
KONSEC Kolab Server is a highly scalable, cluster-capable messaging and collaboration server that is based on the outstanding open source project, Kroupware. The KONSEC Konnektor is a simple client extension that gives Outlook complete group functionality through the Kolab Server, which employs the open standard IMAP together with ACLs, thus enabling you to collaborate in a unique mixed Windows/Linux environment.
The deepOfix Mail Server makes it possible for organizations with minimal technical expertise to have robust server infrastructure. deepOfix offers unprecented ease of use, doesn't require prior GNU/Linux experience and is backed by a full-time development and support team. deepOfix features LDAP-based directory services for user account management, email delivery, distribution lists, and addressbooks. It also includes built in tools for spam and virus control, webmail, and fetching email.