Free e mail proxy software for linux

IMAP Proxy server is a caching IMAP proxy server. It was written to compensate for webmail clients that are unable to maintain persistent connections to an IMAP server. Most webmail clients need to log in to an IMAP server for nearly every single transaction.

This behaviour can cause tragic performance problems on the IMAP server. imapproxy tries to deal with this problem by leaving server connections open for a short time after a webmail client logs out.

When the webmail client connects again, imapproxy will determine if theres a cached connection available and reuse it if possible.

How does imapproxy keep track of which server connection is for which user?

Upon the first successful login to the real IMAP server (through the proxy), imapproxy fills in a little record that contains the username, an md5 digital signature of the password and the server socket descriptor thats being used.

After you log out and then log back in again, imapproxy just has to find a record that matches your username and password. These records are stored in a hash table (with the username being the hash key) in memory, so the lookups are pretty fast.

Can IMAP Proxy support multiple backend servers?

If you want IMAP Proxy to be able to proxy to multiple backend IMAP servers, you can run multiple instances of IMAP Proxy and make sure each instance is looking at a different configuration file.

Before you do this, take a look at perdition which appears to have been designed with this specific task in mind.

YAZ Proxy application is highly configurable and can be used in a number of different applications, ranging from debugging Z39.50-based applications and protecting overworked servers, to improving the performance of stateless WWW/Z39.50 gateways.
Main features:
- Configurable logging
- SRU/SRW server function, to allow any Z39.50 server to also support the ZiNG protocols
- Load balancing across multiple backend servers
- Session-sharing and pre-initialization to improve performance in servers with expensive session initialization
- Configurable request filtering, to keep bad requests from reaching the server
- XML support -- MARC records can be converted to MARCXML, and XSLT-transformations allow the proxy to support arbitrary retrieval schemas in XML
- Load governor function limits requests from aggressive batch-mode clients
- Efficient multiplexing software enables small memory footprint and very high performance
NOTE: The YAZ Proxy, a complete application, is available under the GPL license. Other licensing terms are available to commercial vendors upon request.

SSL Proxy server listens on a TCP port, accepts SSL connections, and forwards them to another local or remote TCP port.
For example, it is possible to create an HTTPS server if you have an HTTP server and you run an SSL Proxy server on port 443 which forwards the connections to port 80.
SSL Proxys design makes it as secure as possible and still perform well.
Enhancements:
- Improved certificate handling (chained certificates are now supported), more error information on SSL protocol errors during SSL_accept(), -U and -D options (buffer size), and a "powered by" logo.

Spike Proxy is an open source HTTP proxy for finding security flaws in web sites.

SPIKE Proxy is part of the Spike Application Testing Suite and supports automated SQL injection detection, web site crawling, login form brute forcing, overflow detection, and directory traversal detection.

To Use:

python spkproxy.py [ optional port argument, 8080 is default ]
Then set up your browser to use that port for both HTTP and
HTTPS proxies.

Then watch the traffic go!

HAVP (HTTP Antivirus Proxy) is a proxy with a ClamAV anti-virus scanner. HTTP Anti Virus Proxy aims are continuous, non-blocking downloads and smooth scanning of dynamic and password protected HTTP traffic.
Havp antivirus proxy has a parent and transparent proxy mode. It can be used with squid or standalone.
Main features:
- HTTP Antivirus proxy
- Scans complete incomming traffic
- Nonblocking downloads
- Smooth scanning of dynamic and password protected traffic
- Can used with squid or other proxy
- Parent proxy support
- Transparent proxy support
- Logfile
- Process change to defined user and group
- Daemon
- Use Clamav (GPL antivirus)
- Operating System: Linux
- Written in C++
- Released under GPL
Enhancements:
- Experimental support was added for chunked Transfer-Encoding, which fixes some broken sites.
- The IGNOREVIRUS configuration directive was added for whitelisting virus names.
- The CLAMBLOCKBROKEN configuration directive was added.
- Detection with AVG was improved.
- HAVP is killed if database reloading fails for Library Scanner.
- The URL is logged when a crashed scanner process is detected.
- The build system updated, adding the --prefix, --sbindir, --sysconfdir, and --localstatedir options.

Japt-Proxy is a JAVA based Caching Proxy for Debians APT-System. Japt-Proxy is very reliable and lightning fast. Japt-Proxy is usually used in environments where several Debian systems have to be kept up-to-date without downloading the same files over and over again from the debian mirrors. Mostly these environments are data centers, Linux-powered companies, schools, public authorities and so on.
Often Japt-Proxy is used because of small sized internet connections but it is also useful to install complete debian systems over the net (read: over the proxy). Even with high volume internet connections Japt-Proxy can dramatically reduce the time to install or update Debian on many machines.
Why Java?
I know there are people out there thinking "Hey? Why Java?". There are a bunch of reasons why people asking those questions. I have a simple answer to all those questions. The answer is, that Java enabled me to easily develop the fastest and most reliable APT-Proxy. Java and the Apache Software Foundation provides such good libraries for this job, that it wasnt very hard to bring up this tool.
If you dont trust, test it - the installation takes less than five minutes!
Doesnt a general proxy server supersede an APT-Proxy?
No, it doesnt. Japt-Proxy knows the characteristics of a Debian archive and their files. It knows, for example, that .deb files wont change, because newer files would have a new name (the version is always part of the filename), hence it wont recheck if there is a newer version of this specific file.
Furthermore you can configure the Japt-Proxy to delete old versions of a package in its cache directory - a general proxy cache would simple delete files that havent been requested for some time.
So, a general caching proxy like Squid is a perfect tool for caching "normal" internet traffic. If you need a proxy for faster APT access - Japt-Proxy is the right tool for you.
Main features:
- Caching of all apt requests from Debian archives
- Multi-threaded architecture which increases the download speed enormously when several machines are requesting packages
- Builds up a partial mirror directory automatically, with exactly the same directory structure and filenames as the original mirror
- Automatic and configurable cache cleanup (purging packages in cache if newer versions exists)
- Makes sources.list configuration easier for multiple machines - if you change your internet backend server you only have to make the change once in Japt-Proxy, instead of on all Debian machines
- Works with multiple architectures
- Backend support for HTTP and FTP
- existing .debs can be copied into the Japt-Proxy cache directory (from a CD or DVD for example) and will be used by the Proxy automatically

Net::Proxy is a Perl framework for proxying network connections in many ways.

SYNOPSIS

use Net::Proxy;

# proxy connections from localhost:6789 to remotehost:9876
# using standard TCP connections
my $proxy = Net::Proxy->new(
{ in => { type => tcp, port => 6789 },
out => { type => tcp, host => remotehost, port => 9876 },
}
);

# register the proxy object
$proxy->register();

# and you can setup multiple proxies

# and now proxy connections indefinitely
Net::Proxy->mainloop();

A Net::Proxy object represents a proxy that accepts connections and then relays the data transfered between the source and the destination.

The goal of this module is to abstract the different methods used to connect from the proxy to the destination.
A proxy is a program that transfer data across a network boundary between a client and a server. Net::Proxy introduces the concept of "connectors" (implemented as Net::Proxy::Connector subclasses), which abstract the server part (connected to the client) and the client part (connected to the server) of the proxy.

This architecture makes it easy to implement specific techniques to cross a given network boundary, possibly by using a proxy on one side of the network fence, and a reverse-proxy on the other side of the fence.

Simple UDP proxy/pipe is an advanced UDP proxy/datapipe/packets forwarder and modifier with multiple functions.

Multiple clients allowed (you can connect many clients you want to this proxy), creation of ACP files (tcpdump capture files, just like a sniffer), packets forwarding (chat style, each packet is forwarded to all the other clients and server connected), packets injection (the tool opens a specific UDP port where you can send your customized packets which will be sent to the server), hexadecimal visualization and plugins support for the modification and visualization of the packets with some example plugins already included (Zdaemon huffman, Doom huffman, Half-life decoding and one for the replacement of the text strings).

Plugins (which work on both Windows and Linux) are very basic to create and use, just take a look at example_sudp.c for more informations.