Citadel is an advanced messaging and collaboration system for groupware and BBS applications. Users can connect to Citadel using any telnet, WWW, or client software. Among the features supported are public and private message bases (rooms), electronic mail, real-time chat, paging, shared calendaring, address books, mailing lists, and more. Unlike other collaboration servers, Citadel provides its own data stores and is therefore extremely easy to install; you don't have to "bring your own" email and database because they're built in. The server is multithreaded and scalable. In addition, SMTP, IMAP, and POP3 servers are built-in for easy connection to Internet mail. Citadel is both robust and mature; it has been in production since 1987.
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.
qmail-ldap is an extension to stock qmail-1.03 to get all user account information from an LDAP database. Its primary target is POP toasters with thousands to millions of users, such as in ISP, FreeMail, and Corporate environments. It features full SMTP/POP3/IMAP server clustering for scaling and high availablity. Additionally there are state-of-the art spam filters, TLS SMTP encrytion, and mailbox quotas. A migration path for Netscape Messenger and Software.com's Post.Office installations is provided.
vpopmail (vchkpw) is a collection of programs and a library to automate the creation and maintenance of virtual domain email configurations for qmail installations using either a single UID/GID or any valid UID/GID in /etc/passwd with a home directory. Features are provided in the library for other applications which need to maintain virtual domain email accounts. It supports named or IP-based domains. It works with vqadmin, qmailadmin, vqregister, sqwebmail, and courier-imap. It supports MySQL, Sybase, Oracle, LDAP, and file-based (DJB constant database) authentication. It supports SMTP authentication combined with the qmail-smtp-auth patch. It supports user quotas and roaming users (SMTP relay after POP authentication).
XMail is an Internet and intranet mail server featuring an ESMTP server, POP3 server, finger server, TLS support for SMTP and POP3 (both server and client side), multiple domains, no need for users to have a real system account, SMTP relay checking, DNS based maps check, custom (IP based and address based) spam protection, SMTP authentication (PLAIN LOGIN CRAM-MD5 POP3-before-SMTP and custom), a POP3 account synchronizer with external POP3 accounts, account aliases, domain aliases, custom mail processing, direct mail files delivery, custom mail filters, mailing lists, remote administration, custom mail exchangers, logging, and multi-platform code.
Arb-Scan is a remote banner scanner written in bash and Perl. It supports 12 different services banner checks (daytime, ftpd, sshd, smtpd, domain, finger, httpd, pop2, pop3, nntp, imapd and snpp). It features IP file reading, logging, random IP scanning, ftp anonymous login checking and VRFY/EXPN smtp checking.
POPauthd is a Perl-based daemon that uses POP to authorize connecting hosts for SMTP relaying. It is particularly useful to authenticate roaming users with IP addresses that change often. The daemon runs in the background, watching the syslog for successful POP logins. When it sees one it enters the IP in sendmail's access database, giving the host authorization to relay through the server. The entries can be expired after a prescribed, configurable period of time with a companion script run via crontab.
Designed as a Perl framework to support many different types of POP and email servers, Mobile POP Relay is useful for mobile users. Once a user successfully authenticates against a POP server, relaying is allowed through the server for a specified time period. It supports Ipop3d, Qpopper, and Vpopd with Sendmail or Exim.
Replex is an administrative tool for managing email on any Unix-like OS. It can handle multiple domains, users, mailing lists, etc. without requiring creation of Unix user accounts for mailboxes or authentication. Replex is written in PHP4 and stores all information in a MySQL database. Replex relies on Postfix for SMTP and Cyrus for IMAP and POP3 accounts.