Mac Mass Mailer is a fully-featured mass mailer that supports message templates and a recipient database. It offers everything you need to create and maintain mailing lists for different needs and send mass messages directly from your computer at a very high speed. It uses Apple Mail's message delivery framework to deliver your messages. The recipient database is fully customizable. You can add as many recipient fields as you want and use them in message templates for the purpose of personalizing your messages.
The QmailToaster is an RPM-based Qmail distribution for CentOS, Fedora, SuSE, and Mandriva. This system is designed for ease of deployment and includes strong anti-spam systems. This includes support for SRS, SPF, DomainKeys, and virtual hosting on the SMTP side. On the user side, this has a Web-based administration interface and supports POP3, POP3 over SSL, IMAP, and IMAP over SSL.
SOGo is a very fast and scalable modern collaboration suite (or groupware). It offers calendaring, address book management, and a full-featured Webmail client along with resource sharing and permission handling. It also makes use of documented standards (IMAP, CalDAV, CardDAV, etc.) and thereby provides native connectivity (without plugins) to many clients such as Microsoft Outlook, Apple iCal, the iPhone, Mozilla Lightning, and a plethora of mobile devices via SyncML. It can reuse any existing email and database infrastructure, avoiding long hours of site restructuring.
Inverse Lightning enhancer plugin enhances the functionalities of the Lightning calendar plugin for Thunderbird. It is meant to add better integration with CalDAV compatible servers such as SOGo. It provides support for CalDAV freebusy information in the scheduling interface and in the addressbook. It manages the iCalendar organizers by taking into account the identities configured in Thunderbird. And it fixes bugs found from time to time in Lightning which are not yet fixed upstream.