Open Source Linux Post-Office Software

Fetchmail is a mail retrieval daemon that can download messages from POP3, IMAP, ODMR and ETRN-based stores, with SSL/TLS security including certificate verification, and pass downloaded mail to a local SMTP or LMTP server, or a message delivery agent such as maildrop.

Convert Webmail to POP3.Is also included a SMTP/POP3 tunneling system that allow send and receive email in a private network HTTP PROXY based. All connection are plugin based. Over 450 email server supported and tested, GMAIL POP3/SMTP over Proxy Network.

Mailcheck is a simple, command line, configurable tool that allows multiple mailboxes to be checked for the existence of new mail messages. It supports both mbox and maildir-style mailboxes. It also supports remote POP3 and IMAP mailboxes.

Set of pure useful Java utilities taking care of common tasks and avoiding re-write of code

OBM is a groupware, email, LDAP, Windows PDC, CRM, and project application mainly used as an Exchange or Notes/Domino replacement with groupware connectors for Outlook, Thunderbird/Lightning, and PDAs. It is highly scalable up to many thousands of users

Qpopper is the most widely-used server for the POP3 protocol (this allows users to access their mail using any POP3 client). Qpopper supports the latest standards, and includes a large number of optional features.

Develop cross-platform tools faster using a C++ Framework proven in commercial software. Classes support logging, sockets, RFC servers (NNTP, SMTP, POP, HTTP), object indexing, ini, tagged databases, file systems, and more. The STDNOJ Namespace, by R.A. Nagy

XCmail is a MIME and multi POP3 server capable mailtool for X11 using the Xclasses layout library. XCmail was designed completely object orientated and by this may be improved easily. <p> XCmail has its own server in the internet. Take a look on it.

A compact, fast and efficient imapd server with maildir support.

Fwsecvpop3d has been designed to be secure, fast and reliable pop3 server. It's easy to configure, supports many authentication features, virtual users (per-domain auth, so the same user can exist in a lot of domains) and is thread based (scalability).

hotwayd/hotsmtpd are POP3/SMTP-HTTPMail gateway daemons. The HTTPMail protocol is used by the mail servers Hotmail, Lycos, Spray and MSN. The hotway suite you can receive and send mail via these services using any POP3/SMTP compliant mail reader.

libpop3 is a very light POP3 library for C. It allows to list, fetch and remove messages from a POP3 mailbox. This library is using the RFC1939 as reference, and uses most basic POP3 commands to provide maximum compatibility across different servers. libpop3 is written in pure ANSI C89 without any external dependencies, thus it can be compiled and used on anything, anywhere. Since it is very light, it is designed to be used as a static library (but you could just as well incorporate its code right into your project).

libspopc is a simple and really thin pop3 client library to be used by small programs, licensed under the GNU General Public License.