Distributed Checksum Clearinghouse (DCC) is a system of clients and servers that collect and count checksums related to mail messages. The counts can be used by SMTP servers and mail user agents to detect and reject bulk mail. DCC servers can exchange common checksums. The checksums include values that are "fuzzy", or constant across common variations in bulk messages.
PHPMailer is an email transport class which features multiple file attachments, CCs, BCCs, REPLY-TOs, HTML messages, redundant SMTP servers, and word wrap, among others. It can send email via sendmail, PHP mail(), or with SMTP. Methods are based on the popular AspEmail active server component.
Collax Groupware Suite is a complete collaboration, e-mail, and messaging server with Outlook MAPI support. It offers enterprise email server functions, anti-spam and anti-virus filters, GUI management, a file server for SMB, NFS, FTP, and Apple shares, backup/restore server, IM server, and fax and SMS server. The groupware offers AJAX Web mail, calendar, team calendar, contacts, and tasks, and supports ActiveSync for mobile devices. It is free for private or commercial use of up to five users.
Lire is a pluggable log analyzer. It has analyzers for over 25 log file formats, ranging from Apache WWW log files to iptables firewall logs and CUPS printing logs. Reports are generated in 9 different output formats, ranging from Excel 95 to PDF to HTML, optionally with included graphs.
Maildrop is a powerful email filter/delivery agent. It supports mbox-style mailboxes and maildirs (a mail storage format used by Qmail). Its mail filtering language supports RFC822 parsing and GDBM/Berkeley DB database files. The maildrop package also includes a command-line tool to perform various operations on MIME messages.