Free smtp relay server software for linux

Streamnik Server project is an IPTV server based on the open codecs Ogg/Vorbis and Ogg/Theora. It can stream a number of different channels and is optimized to run on leased (virtual) servers. The program schedule is defined by an SQL database table and can be changed at runtime.

SQL Relay is a persistent database connection pooling, proxying and load balancing system for Unix and Linux.
Main features:
SQL Relay is ideal for:
- speeding up database-driven web-based applications
- enhancing the scalability of database-driven web-based applications
- distributing access to replicated databases
- throttling database access
- accessing databases from unsupported platforms
- migrating applications from one database to another
SQL Relay supports the following database backends:
- Oracle
- MySQL
- mSQL
- PostgreSQL
- Sybase
- MS SQL Server
- IBM DB2
- Interbase
- Sybase
- SQLite
- ODBC
- MS Access
The SQL Relay client APIs support advanced database operations such as bind variables, multi-row fetches, client-side result set caching and suspended transactions. SQL Relay has native client APIs for the following languages:
- C
- C++
- Perl
- Python
- PHP
- Ruby
- Java
- TCL
- Zope
SQL Relay provides drivers for the following database abstraction layers:
- Perl DBD
- Python DB
- Ruby DBD
- PHP Pear DB
An application coded using another databases native client API may be able to use SQL Relay without modification. SQL Relay provides drop-in replacement libraries for:
- MySQL
- PostgreSQL
SQL Relay also features:
- command line clients
- a GUI configuration tool
- extensive documentation
Enhancements:
- Several contributed patches were applied.
- Oracle stability was improved.
- Support for Oracle OS-authentication was added.
- The maxlisteners option was added.
- Support for Sybase stored procedures which return result sets was added.
- A Zope empty-result set bug was fixed.
- Support for Mac OS X, Solaris, and Cygwin was improved.

Jsmtpd is a compact SMTP daemon (Email server), entirely written in Java. Jsmtpd project is basicly able to receive E-mail following the SMTP protocol, described in RFC 821. Each others functionnalities are implemented as plugin modules, allowing the core to remain small and easily understaindable.
As now, Jsmtpd is able to receive mail, check its recipients (ACL-SimpleACL plugin), check for viruses (filters-ClamAVFilter, connects to a ClamAV daemon), check for spam using the Java Jasen engine (filters-JasenAntiSpamFilter) or a spamassassin daemon, check senders via RBL plugin or blacklist plugin. Emails can be delivered localy using the mailbox writer (DeliveryServices-UnixMailboxWriter), or to a remote STMP server (DeliveryServices-RemoteSmtpSender). DNSQueries are also provided by a plugin (DNSJava).
Version 0.4 (Brinsop) has introduced two new extensions : TLS(SSL) support, and SMTP authentication.
Jsmtpd comes with three main services :
The receiver service : Its job is to listen for incoming STMP connection, chat with the client in order to receive E-mails according to ACL plugin.
The second service is the mail queue services. It holds the received mails (loaded or writen to disk). Whenever possible, it processes mails to the delivery service.
The delivery service is a filter plugin tree ending by a delivery service. A filter is basicly a piece of code that answers yes or not to an incoming email. Mails are then checked agains theses plugins, following a tree model. A the end of the chain, the mail is droped if it does not match the filters, or a delivery plugin is invoked to deliver the mail. For now, only two delivery services can be routed using the ACL plugin : local or remote mail.
Jsmtpds design is heavily based on plugins. Most functionnalities are implemented as plugins. Plugins interfaces are simple to understaind and implement. With minimal time spent learning Jsmtpd, you can rewrite how Jsmtpd handles :
Dns queries
Acces control list (who can do what on the runnning server)
Deliveries : you want to put your mail directly into your custom application ? Write a plugin !
IP filtering
Mail filtering
This server is designed to provide efficient ways to stop unsollicited mail or mail containing viruses. A Jsmtpd deamon cant be set as open relay ( youll have to write a plugin to do so ;).
Filtering spam can be done at two levels. Ip based filtering will reject connections from well known spammers or open relais smtp servers (ie misconfigured mail servers used by spammers to relay their mails). Content based filtering allows to check mail containing spam (using Spamassassin or Jasen) or viruses (using Clam Antivirus).
If you cant find a filter matching your needs, you can easily write your own and plug it in Jsmtpd.
Jsmtpd is intended to remain small, understaindable and (quite) fast. Without using filters plugin, minimal process is applied to the email data, providing best performances. If you need a more powerfull (in terms of functionnalities) email service solution, I recommend you to check out the jakarta James project and their mailet API.
This server runs over a Java Virtual Machine, and should make intrusions like buffer overflow more difficult to success.
Enhancements:
- In this release, code has been cleaned up and refactored (common-loggings by example).
- It includes several bugg fixes in ldap plugins and dns resolver mainly, and improved thread usage.
- New plugins have been added : maildir writer, lmtp delivery(experimental) and spf/greylist.

Net::Server is an extensible, general Perl server engine.
SYNOPSIS
#!/usr/bin/perl -w -T
package MyPackage;
use Net::Server;
@ISA = qw(Net::Server);
sub process_request {
#...code...
}
MyPackage->run(port => 160);
exit;
Main features:
- Single Server Mode
- Inetd Server Mode
- Preforking Simple Mode (PreForkSimple)
- Preforking Managed Mode (PreFork)
- Forking Mode
- Multiplexing Mode using a single process
- Multi port accepts on Single, Preforking, and Forking modes
- Simultaneous accept/recv on tcp, udp, and unix sockets
- Safe signal handling in Fork/PreFork avoids perl signal trouble
- User customizable hooks
- Chroot ability after bind
- Change of user and group after bind
- Basic allow/deny access control
- Customized logging (choose Syslog, log_file, or STDERR)
- HUP able server (clean restarts via sig HUP)
- Dequeue ability in all Fork and PreFork modes.
- Taint clean
- Written in Perl
- Protection against buffer overflow
- Clean process flow
- Extensibility
Net::Server is an extensible, generic Perl server engine. Net::Server combines the good properties from Net::Daemon (0.34), NetServer::Generic (1.03), and Net::FTPServer (1.0), and also from various concepts in the Apache Webserver.
Net::Server attempts to be a generic server as in Net::Daemon and NetServer::Generic. It includes with it the ability to run as an inetd process (Net::Server::INET), a single connection server (Net::Server or Net::Server::Single), a forking server (Net::Server::Fork), a preforking server which maintains a constant number of preforked children (Net::Server::PreForkSimple), or as a managed preforking server which maintains the number of children based on server load (Net::Server::PreFork). In all but the inetd type, the server provides the ability to connect to one or to multiple server ports.
Net::Server uses ideologies of Net::FTPServer in order to provide extensibility. The additional server types are made possible via "personalities" or sub classes of the Net::Server. By moving the multiple types of servers out of the main Net::Server class, the Net::Server concept is easily extended to other types (in the near future, we would like to add a "Thread" personality).
Net::Server borrows several concepts from the Apache Webserver. Net::Server uses "hooks" to allow custom servers such as SMTP, HTTP, POP3, etc. to be layered over the base Net::Server class. In addition the Net::Server::PreFork class borrows concepts of min_start_servers, max_servers, and min_waiting servers.
Net::Server::PreFork also uses the concept of an flock serialized accept when accepting on multiple ports (PreFork can choose between flock, IPC::Semaphore, and pipe to control serialization).

smtp-vilter is a high-performance content filter for sendmail, which detects email viruses and spam.

smtp-vilter can pass, discard, or simply mark an email based on the results of a content scan. It relies on third-party products for the actual content scan. It uses the milter API to communicate with sendmail, and backends to communicate with the actual scanning engines.

The backends can be chained to perform a series of checks on each message in one run.

QEMU Server Tools is a set of simple command-line scripts for managing multiple QEMU VMs easily without requiring a graphical frontend.

QEMU Server Tools organizes VMs into directories and mimics the usage of command line tools from VMware Server.