Rspamd is an anti-spam system designed to work faster than SpamAssassin by using the event model and various optimizations. Its most important features include regexp and Lua rules for filtering different parts of messages, a number of built-in functions for analyzing messages, fuzzy hash support, SURBL filters, email and character table support, a control interface for remote managing and stats gathering, a Lua plugin system, statistics support (OSB/Bayes), and an AJAX-based Web interface.
Thunderbird is a total redesign of the Mozilla mail component to produce a cross-platform, stand-alone mail application using the XUL user interface language. It has many new features, among them the ability to customize your toolbars the way you want them. a new look and feel with a large number of downloadable themes which alter the appearance of the client, and the ability to add UI extensions.
GroupOffice is a groupware suite that takes your office online, implementing online collaboration and CRM. It allows you to share projects, calendars, files and email online with co-workers and clients. It is easy to use and fully customizable. It also features synchronization with PDAs and Outlook.
The SeaMonkey project is a community effort to develop an all-in-one Internet application suite. It contains an Internet browser, email and newsgroup client with an included Web feed reader, HTML editor, IRC chat, and Web development tools, and is sure to appeal to advanced users, Web developers, and corporate users. It uses much of the Mozilla source code powering such successful siblings as Firefox, Thunderbird, Camino, Sunbird, and Miro.
Jaro Mail is an integrated suite of interoperable tools for GNU/Linux and Apple/OS X to manage email communication in a private way, without relying on online services (in fact, encouraging users to store email locally). It mainly features a system for mailinglist filtering, address-book integrated whitelisting, and long-term email storage and archiving with functions for fast search and usage statistics. It makes internal use of customized versions of popular Unix tools like Mutt, Fetchmail, Procmail, Mairix, and Msmtp.
dl is a file exchange service that allows you to upload any file to a Web server and generate a unique ticket for others to download. The ticket is automatically expired according to the specified rules, so that you don't need to keep track or cleanup afterward. dl also allows you to grant an anonymous, one-time upload for others to send you a file, without the requirement of account management. dl is usually installed as a replacement for email attachments due to its simplicity (though it can be used in other ways).
IndiMail is a messaging platform built using qmail and other messaging software. IndiMail has the ability to distribute the users in a domain across multiple hosts. IndiMail has multiple queues (called a queue collection), which can achiever very high concurrencies. The system IDs and configuration files used by IndiMail are all configurable through a set of environment variables, allowing you to customize IndiMail the way you want. IndiMail does not use hard-coded uid/gid in the executables, which makes it easy to distribute a binary package. IndiMail has features that any modern email server should have: SMTP, QMQP, QMTP, IMAP, POP3, DKIM, BATV, greylisting, filtering capability, and spam/virus control.
libtld is a library used to extract the TLD from a URI and to check email validity. This allows you to extract the exact domain name, sub-domains, and all the TLD (top level, second level, third level, etc.). The problem with TLDs is that you cannot know where the domain starts. Some domains can use one top-level domain, others use two, etc. However, it may be useful to know where the domain is to have the exact list of sub-domains. For example, if you want to force www. at the start of the domain name if no other sub-domains are specified, then you need to know exactly how many TLD are defined in a URI. The libtld offers one main function: tld(), which gives you a way to extract the TLD from any URI. The result is the offset where the TLD starts. This gives you enough information to extract everything else you need. For emails, the library is capable of parsing a string that represents a list of email addresses to be verified. The verification includes a check of the domain name and its TLD.
MailSteward will archive all of your email in a database for easy retrieval, without touching or modifying the email in your email client program. Just click on the Store Email in Database button and MailSteward will go to work storing copies of all your email, both text and HTML versions, and attachments, into a relational database file. You can then retrieve email and attachments from the database by searching on Date, From, To, Subject, Mailbox, or Body text.