Free sendmail milter software for linux

SPF Sendmail milter is a Sendmail filter that implements the Sender Policy Framework technology with help of libSPF2 library.
It checks SPF records to make sure that the email is authorized by the domain name that it is coming from. This prevents email forgery, commonly used by spammers, scammers and email viruses/worms.
It can reject messages on SPF hardfail result. Also it adds the standard Received-SPF header with SPF results to the scanned messages.
This filter aims to be lightweight, reliable, and simple. Its written in C. Although this filter is a stable itself, libSPF2 is a beta software and can be unstable. It can affect to the filter stability. Please, use it in the production environment with caution.
Main features:
- It has a hosts/networks whitelist;
- It can reject messages on SPF hardfail result;
- It can add the standard header with SPF results;
- It logs all filter activities to syslog.
- Small code (does not exceed 320 lines);
- Fast work;
- Stability (production quality);
- Low resources are required;
- No temporary files are created.
Enhancements:
- Cosmetic enhancements were made.

Sendmail::Milter is a Perl interface to sendmails Mail Filter API.

SYNOPSIS

use Sendmail::Milter;

my %my_milter_callbacks =
(
connect => &my_connect_callback,
helo => &my_helo_callback,
envfrom => &my_envfrom_callback,
envrcpt => &my_envrcpt_callback,
header => &my_header_callback,
eoh => &my_eoh_callback,
body => &my_body_callback,
eom => &my_eom_callback,
abort => &my_abort_callback,
close => &my_close_callback,
);

sub my_connect_callback;
sub my_helo_callback;
sub my_envfrom_callback;
sub my_envrcpt_callback;
sub my_header_callback;
sub my_eoh_callback;
sub my_body_callback;
sub my_eom_callback;
sub my_abort_callback;
sub my_close_callback;


BEGIN:
{
# Get myfilters connection information
# from /etc/mail/sendmail.cf

Sendmail::Milter::auto_setconn("myfilter");
Sendmail::Milter::register("myfilter",
%my_milter_callbacks, SMFI_CURR_ACTS);

Sendmail::Milter::main();

# Never reaches here, callbacks are called from Milter.
}

Sendmail::Milter is a Perl extension to sendmails Mail Filter API (Milter).

Note: You need to have a Perl 5.6 or later interpreter built with -Dusethreads.

Sendmailizer provides a Sendmail and qmail log file analizer.
Sendmailizer performs MTA log file analysis and generates email usage reports, with general stats and statistics per user.
Installing
1. move where sendmailizer.pl lives
2. Modify sendmailizer.conf (parameters are self-explanatory)
(logfile should be: /var/log/maillog)
(please especify local domains: mydomain.com,mydomain.net...)
3. Try with ./sendmailizer.pl sendmailizer.conf
Enhancements:
- Some bugfixes were made, including a data loss bugfix.
- The report design was changed.

smf-clamd is a Sendmail milter for the ClamAV (Clam AntiVirus).
Sendmail filter for ClamAV aims to be lightweight, reliable and simple. Sendmail filter for ClamAV is written in C.
Main features:
- It has a hosts/networks whitelist;
- It can scan messages less than a defined size only;
- It rejects infected messages at the SMTP DATA stage;
- It can add an information header with scan results to scanned messages;
- It can log all milter activities through the syslog service.
Advantages:
- Small code;
- Fast work;
- Stability (production quality);
- Few system resources are required;
- No temporary files are created.
Enhancements:
- A workaround for the Sendmail socket unsafe error on some platforms was implemented.
- Clean email messages logging was removed.
- Configuration file, default user, and working directory were changed.
- The format of log records was changed.
- Some samples of start-up scripts were added.
- The new TODO tasks were added.
- Cosmetic enhancements were made.

usendmail is a replacement for the sendmail program in the qmail package.
Nomenclatura:
- usendmail is usendmail
- qsendmail is the qmail sendmail clone
- sendmail is plain old sendmail (getroot)
Enhancements:
- Adds more sendmail options (-G, -L, -X).
- the -f option now also influences the generation of the "from" header field, unless its already there or the QMAILHOST or QMAILUSER environment variables are set.

SMC non-context E-mail filter - is an software application designed to significantly reduce the amount of SPAM/UCE (junk-mail) you receive. 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 milter (plugin), which stops the junk-mail 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 10-minutes checks, which setted by the "maxcount" configuration parameter.
And the third of original algorithms is "auto-authentication" 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 previous "check delay" algorithm.
Enhancements:
- CLOSE_WAIT problems have been solved (a critical bug).
- There is a critical bugfix to prevent DNS storms.
- All of the resolver functions use the local resolver context.
- Automake and autoconf support have been added.

Sendmail X is a modularized message transfer system consisting of five (or more) persistent processes, four of which are multi-threaded.
A central queue manager controls SMTP servers and SMTP clients to receive and send email messages, an address resolver provides lookups in various maps (including DNS) for mail routing, and a main control program starts the others processes and watches over their execution.
The queue manager organizes the flow of messages through the system and provides measures to avoid overloading the local or remote systems by implementing a central control instance.
Sendmail X is simple to configure using a syntax that is easy to understand and use. It is intended to be used as a secure and efficient mail gateway. It does not provide any mail content modification capabilities such as address masquerading.
Enhancements:
- This version has better error logging for STARTTLS problems and a libpmilter fix.

Mail::Sendmail is a simple platform independent mailer.
SYNOPSIS
use Mail::Sendmail;
%mail = ( To => you@there.com,
From => me@here.com,
Message => "This is a very short message"
);
sendmail(%mail) or die $Mail::Sendmail::error;
print "OK. Log says:n", $Mail::Sendmail::log;
Simple platform independent e-mail from your perl script. Only requires Perl 5 and a network connection.
Mail::Sendmail contains mainly &sendmail, which takes a hash with the message to send and sends it. It is intended to be very easy to setup and use.
Main features:
- Automatic time zone detection, Date: header, MIME quoted-printable encoding (if MIME::QuotedPrint installed), all of which can be overridden.
- Bcc: and Cc: support.
- Allows real names in From:, To: and Cc: fields
- Doesnt send an X-Mailer: header (unless you do), and allows you to send any header(s) you want.
- Configurable retries and use of alternate servers if your mail server is down
- Good plain text error reporting
Version restrictions:
- Headers are not encoded, even if they have accented characters.
- No suport for the SMTP AUTH extension.
- Since the whole message is in memory, its not suitable for sending very big attached files.
- The SMTP server has to be set manually in Sendmail.pm or in your script, unless you have a mail server on localhost.
- Doesnt work on OpenVMS, I was told. Cannot test this myself.