Free bulk email sender software for linux

Mozilla Thunderbird is a full-featured email, RSS and newsgroup client that makes emailing safer, faster and easier than ever before.
It offers some advantages over other mail clients, including junk mail classification. Built from Mozilla code, Mozilla Thunderbird uses Gecko, the most standards-compliant rendering engine in existence.
In addition to the feature set found in Mozilla Mail, Thunderbird has several new features and improvements to make your mail and new experience better.
Main features:
- Adaptive Junk Mail Controls
- RSS Integration
- Saved Search Folders
- Saved Search Folders display messages based on previously set search criteria. For example, instead of filtering messages into a new folder, you can create a Saved Search Folder that lists all the messages received from a certain person over the past 30 days, even if those messages are stored in different folders and subfolders.
- Global Inbox Support
- POP3 users can now combine all of their POP3 accounts into a single global inbox under local folders.
- Message Grouping
- You can now group messages in a folder by attributes such as date, sender, priority or a custom label. For instance, a folder grouped by date will group messages from today, yesterday, last week, etc. into self-contained groups in the message list pane. (View > Sort By > Grouped By Sort)
- Privacy Protection
- In order to help protect your privacy, Thunderbird now automatically blocks remote image requests in emails from senders you dont know.
- Comprehensive Mail Migration from other Mail Clients
- Switching to Thunderbird has never been easier since Thunderbird can now migrate all of your email data including settings, mail folders and address book data from common mail applications such as the Mozilla 1.x Suite, Outlook Express, Outlook and Eudora.
Enhancements:
- Unescaped URIs passed to external programs
- Privilege escalation through chrome-loaded about:blank windows

SMS Server Tools provide the sms server tools for the send sms, bulk sms, through linux on cdma support mobile.
The SMS Server Tools (smstools) were made to send and receive SMS from one or many GSM modems.
They include a send/receive daemon and some sample scripts to build an SMS email gateway and for logging into an SQL database. The daemon waits for files in an outgoing spool directory and sends them.
It puts all received SMS in an incoming spool directory, and can call any external program for incoming or outgoing notification. This software support text messages in 7 and 16 bits (UCS2), as well as 8 bit binary messages.
Enhancements:
- String buffer termination errors have been fixed.
- This release reduces the risk of abnormal program termination in case of bad entries in the config file and bad modem answers.
- It also reduces the risk of missing the last digit in received phone numbers.

Junk Mail Buffering Agent is a tool for preventing delivery of email until the sender has confirmed their address.

Junk Mail Buffering Agent can be used in conjunction with a spam filter to prevent delivery of spammy-looking email unless the sender is confirmed as valid.

jmba is designed to be used in conjunction with a spam filter such as QSF and the mail processor procmail. When the spam filter says it thinks an email is spam, it can be passed to jmba.

jmba will queue it and send an email to the sender containing a key; if the sender replies, the original email is "unfrozen" from the queue and delivered.

Email sends email to remote SMTP servers via the command line, which makes it useful in cron jobs. It will send to any RFC standard remote ESMTP server, and will allow you to encrypt, sign, and design your message on the fly.
It has the capability to use signature files with dynamic options, address book functionality, and users can also attach pictures, binary files, documents, or whatever they want. It is completely compatible with GNUPG for encryption and signing, and is easy to configure and use.
Enhancements:
- A bug where an assert caused an abort when encrypting any message with GnuPG under Cygwin has been fixed.
- Compile time problems where the compiler would complain about SIG* being undeclared have been fixed.
- There is some minor source code cleanup.

ASK is a spam killer. This program (Active Spam Killer, or ASK for short) takes an "Active" approach in solving the problem: Everytime an email is received, a message is sent back to the sender asking for confirmation. If that sender does not confirm the message, it remains queued for delivery. If the sender confirms, the message is delivered and removed from the queue. The "confirmed" senders will be added to your "whitelist" and will never be sent another confirmation. Messages from these emails will always be delivered immediately . You can also specify an "ignorelist" for emails that should be always ignored and a "blacklist" that will cause a nastygram to be sent back to the sender everytime an email is received.

There are many traditional approaches to avoiding spam. The most common approach is based on "content-filtering": a program that attempts to classify incoming mails based on their content. This works partially, but in reality, its somewhat easy to find ways to avoid it.

ASK takes advantage of the fact that most spammers use invalid or fake "From:" address in their messages. When a new message arrives and the sender is unknown, ASK sends a "confirmation message" back, informing the sender that the original message has been queued, pending confirmation. When the sender confirms (a simple reply), ASK delivers the original message and adds the sender to a "whitelist". Further messages from this sender will be immediately delivered. It is also possible to ignore messages based on specific criteria, like senders email, subject and so on.

The goal of ASK is to block Spam mail before it is delivered to your mailbox. As we know, filtering alone is not effective since many times Spam mail contains no detectable elements.

ASK should be invoked from .forward (or .procmailrc if you are using procmail). The incoming message should be piped to ASK, which will be in charge of doing the actual delivery.

When ASK receives an email, if first checks the email address against your "ignorelist". If the address is listed there, its ignored completely. Then, the message is checked against your "blacklist". If its there, a nastygram is sent back to the sender with something like "Please stop sending me emails" in the Subject line.

The real fun happens when an email comes from an unknown user (i.e, someone not in any of your lists). In this case, ASK calculates the MD5 checksum of the message + a secret MD5 key (configured during installation time). This number is sent as part of a "confirmation message" back to the user. If the user replies to it, the confirmation number (in the subject) is recognized, the message is dequeued and delivered. If the user does not reply, the message remains queued until its removed.

The program has some intelligence to deal with specific cases. For instance, if a mail is sent to a non-existing user, the error message from mailer-daemon is ignored. This avoids seeing lots of "invalid user" messages in your inbox.

Another interesting "twist" is that messages coming from your own email address are never trusted. If the spammer knows your address he could easily fake your own address as the From: line. Messages coming from you will be identified by a "mailkey", a piece of string you always put on your message by default (maybe a piece of your own signature). Note that this has the added side-effect of allowing any messages coming in reply to a message you sent to someone (as long as that person keeps your "mailkey" in its quoted reply, a practice common these days).

The program never deletes any messages. For instance, if you send yourself a message without your mailkey (a possible Spam), it will be saved in a "Junk" mailfolder (you can specify this folder during the configuration).

spfmilter provides a Sender Policy Framework (SPF) milter for Sendmail.
spfmilter is a milter (sendmail mail filter) which implements the Sender Policy Framework (SPF). SPF is a strategy for preventing junk mail. The SMTP standard for email allows anyone to forge anyone elses email address.
SPF verifies that the Sender address of an email message matches (according to some policy) the client IP address that submitted it.
The idea of SPF is to prevent email forgery. Each participating site sets up a little definition of which hosts are allowed to send mail claiming to be from that site. When another site receives mail, it checks the permitted-senders definition for the originating site. If the check fails, the mail is rejected.
Setting up the permitted-senders definition is very easy, you go to the SPF Wizard and fill out a little form, then put the resulting string into your DNS records. This milter implements the second half of SPF, checking the mail you receive against other sites SPF records.
Enhancements:
- Some improvements to the redhat rcscripts. (Paul Howarth)
- Deal with the unknown-family connections which occasionally show up on some OSs, such as Solaris. (Joel Lord)

Sendmail Confirmation System is an Sendmail milter plugin that is designed to reduce the amount of junk email received. SMC uses a dynamic local and DNS based remote "whitelists" (for known/trusted senders), DNS based "blacklists" (for undesired senders), and an original "autoauthentication" system (for unknown, but legitimate senders). In additional SMC has a set of useful features which allows to preserve mail recipients from dangerous message attachments, HTML includes. SMC is an Sendmail tm milter (plugin), which stops the junk mail messages without receiving one.
SMC uses 3 original algorithms, one of which is "Check relay by NS" simulates a dynamical whitelist and will always accept the messages from mail systems satisfying to following conditions:
1) Mail domain name (the host part of the senders e-mail address) must have an MX records;
2) Mail domain name and the connection host address must be resolved;
3) Connection host must be listed at the one of nameservers which hold the senders mail domain name.
The second from the developed algorithms is a "check delays" algorithm which is based on statistical check of delivery delays, generated by a [tempfail] return code, that allows to exclude a direct receiving of a mail, which not passed through the standard mail server.
NOTE: Using this feature the delivery of the mail from unknown, but legitimate senders will be delayed for a count of 5-minutes checks, which setted by the "maxcount" configuration parameter.
And the third of original algorithms is "autoconfirmation" algorithm: The sender of a "mail contact" (sender-recipient pair) means as authenticated (whitelisted) if the filters statistics module has registered the both of a sended forward (request) and a recieved backward (reply) messages of this contact. The messages from the such authenticated senders will never be delayed by the previos "check delay" algorithm.
Enhancements:
- Add checks to prevent overwrite all configuration data during install.
- Minor bug fix in ns-relay code.

Sender Rewriting Scheme Library is an ANSI C implementation of the Sender Rewriting Scheme.

It solves the "broken forwarding" problem imposed by SPF (Sender Policy Framework), which is an SMTP Anti-Forgery technology currently under development and deployment worldwide.

And dont think ive done it right either. If its simple and you feel like it submit a patch, otherwise just be as verbose as you can in describing your errors. Please submit output using the -DDEBUG and -DVDEBUG compile time options as these are of the greatest help.