Free pop3 imap4 software for linux

jPOPc project is a simple, threaded, multi-part, UTF-8 compliant POP3 email client.
Main features:
- threaded
- very fast
- supports Base64 encoded attachments
- supports Quoted-Printable encoded attachments
- flexible configuration

POP3 Virus Scanner Proxy is a full-transparent proxy daemon which scans all mails for viruses using third party scanners (built-in support for AVPD and Trophie).

You have to set up a port redirection in the linux-netfilter (iptables) so that all connections from e.g. inside your office to any POP3 server outside in the world will not leave your router, but come a local port, on which POP3VScan listens. POP3VScan receives from the linux kernel the original destinations of packets (the POP3 server outside in the world) and will connect to them.

All data we receive from the client will be sent to the server, and vice versa. With a little enhancement: we parse the neccessary parts of the POP3 protocol and when an email is sent from the server, we store it into a file, invoke a virusscanner and send it if it is good, or we just replace it with a virus notification. It should be possible to use all scanners using the scannertype=basic. Also POP3VScan provides scannertype=avpd for high-speed scanning using Kaspersky Anti-Virus for Linux, every C programmer can easily adept other scan-daemons (trophie, sophie, antivir, ...).

Neither the client nor the server has to be configured, none of them will take notice that theres a mailscanner (except the client when he gets a virus notification or if he looks into the header, and the server gets our ip as source).

Perl Pop3 is a POP3 server fully implemented in Perl.
The advantages over other POP3 servers are that it is not a memory hog, and can be used to connect to databases for authentication.
Also, its code is easy to extend for any other uses, like POP-before-SMTP and extended logging.
Main features:
- Does not read the mailbox into memory, it reads what it needs as it processes the mailbox, so its memory requirements are low.
- Most email delivery is just printing out to the client; this is done in a fast and efficient way.
- It uses the systems users in the default unix way, but it can be changed to read users off a database (using DBI/DBD). It is prepared to use the database right away and can be extended or configured to use existing systems.
- It can be use to solve the smtp authentication via popauth or relay-domains (with sendmail) so users can be permitted to send smtp mail after pop3 authentication. This has been an effective solution for roaming users.
- Logging can be extended beyond the use of text files to any other method available in Perl, including database systems.
- Also, security is not an issue, as input is strictly controlled.
Using an easily modifiable daemon as part of a e-mail solution can be of great advantage over other existing systems in other languages. Further development will also try to incorporate more easily configurable extensions and plugins, so rapid deployment and extensibility is achieved.
Installation:
For installation instructions and configuration please see the INSTALL file. For more detailed information, consult the DOC file.

WMpop is a Window Maker DockApp for monitoring a local (mbox format) or POP3 mailbox. WMpop project displays:
- number of mails in the mailbox (or unread mails if checked in the preference screen),
- a scrolling text with the email address of the senders (only for local mailbox for the moment),
- and a status led, indicating mail checking progression and errors.
WMpop can be configured via a graphic interface written in GTK+. The configuration interface let you define parameters of your POP3 server, and let you personalize the app (changing icons or sound and choosing an external command to launch on demand).
It is internationalized, with French translation. You can also run several instances of the program of different mailboxes (remote or local).

Poprox is a POP3 and SMTP transparent filtering proxy. The project does virus scanning using libclamav and is comparable to p3scan in philosophy.

Its design is based on a multi-process architecture which allows the detection of libclamav crashes. When this occurs, Poprox is able to delete the offending mail.

Debug mode can be toggled by sending a SIGUSR1 signal to the main process. Interactions with users can be translated in any language by using a simple template system.

NullPop is a POP3 server that allows logins, but never returns any email.
NullPop is useful for certain setups where the user needs an account setup in their mail client, but no real mail will ever be received.
Installation:
A basic install procedure looks like this.
# cd nullpop-0.x
# ./configure
# make
# make install
By default nullpop will install to the /usr/local/libexec/ path. You may want to specify a different prefix with the --prefix argument to ./configure.
Execute the following command for more options:
./configure --help
Enhancements:
- Added documentation

popa3d project is a tiny POP3 daemon.
It is designed with security as the primary goal. You can read more about its design, check out the change log, or download a popa3d tarball (the latest stable version is recommended) and refer to the documentation inside.
Enhancements:
- A couple of optimizations specific to x86-64 have been applied to the included MD5 routines.