qmail

Roundcube webmail

Roundcube is a full featured webmail with a nice interface.

RoundCube 0.8 showing its new skin

qmail + vpopmail + Dovecot | Roberto's qmail notes

Quoting D. J. Bernstein definition

qmail is a secure, reliable, efficient, simple message transfer agent. It is designed for typical Internet-connected UNIX hosts

References

You can find a comprehensible introduction on how a mail server works in this page of the Dovecot site. The qmail newbie's guide to relaying by Chris Johnson is very clear. It’s very suitable reading material for someone who’s just getting started.

Disclaimer

The aim of this short guide is NOT to teach you how a mail server works, even though by the time you’re finished reading it you will hopefully have a working e-mail server. These notes just serve as a reminder of the main steps to follow in order to build a quick installation of qmail and related software. I published them because of the lack of any up-to-date documentation concerning the qmail “distributions” I was familiar with, hoping that these notes could be useful to others out there. And I created this guide partly just because I enjoy doing this kind of thing.
Therefore, to learn in depth how a mail server works, you are invited to read carefully at least the references I will mention in each page.

Secondly, I am NOT responsible for what you do with your server :) Use my guide at your own risk.

Finally, comments, criticisms and suggestions are always welcome! :-p

Which distro?

These notes have been written without a specific Linux distribution in mind. I tested them on my Slackware virtual mail servers, both 64 and 32 bit, and a number of guys out there can confirm that it works with other common distributions.

Is this a toaster?

According to the DJB's definition of a toaster, the answer would be yes. I personally consider a toaster something a la Bill Shupp or qmailtoaster, which comes with the packages included. Since I prefer to let you check for the latest versions of everything yourself, strictly speaking this shouldn’t properly be considered a toaster. I would simply call this site “Roberto’s qmail notes” instead. At any rate, I’ve included a paragraph about qmail toasters here just to satisfy the search engines -as most people come here actually looking for a toaster :)).

Before we start...

As I am not  a native english speaker, I will gladly accept every hint to improve the understanding of this guide.

Patching qmail

Changelog

The complete changelog is inside the patch file.

  • 2014-11-20
    -the SSLv3 connection upon the auth was switched off because of security reasons (thanks to Florian)
  • 2014-11-15
    -modified the QUEUE_EXTRA variable in extra.h to record the Message-ID in the qmail-send's log. Thanks to Simone for the hint.
  • 2014-04-14
    -added qmail-maxrcpt patch, which allows you to set a limit on how many recipients are specified
  • 2014-03-10
    -added qmail-smtpd-liberal-lf patch, which allows qmail-smtpd to accept messages that are terminated with a single \n instead of the required \r\n sequence. This should avoid some "read failed" reject.
  • 2013-12-30
    -added qmail-SRS patch. You have to install libsrs2 now.
    -the character "=" in the sender address is now considered valid by chkuser in order to accept SRS
  • 2013-12-18
    -added qmail-date-localtime patch
    -added qmail-hide-ip patch
    -the original greetdelay by e.h. has been replaced with the improved patch by John Simpson. Now
    communications trying to send commands before the greeting will be closed. Premature disconnections will be
    logged as well.
    -CHKUSER_SENDER_FORMAT enabled to reject fake senders without any domain declared (like <foo>)
    -chkuser logging: I slightly modified the log line adding the variables' name just to facilitate its interpretation
    -added qmail-moreipme patch
    -added qmail-dnsbl patch (more info here)
  • 2013-12-05
    added two patches to make qmail rfc2821 compliant
  • 2013-11-23
    any-to-cname patch added

I have created a combined patch including the latest versions of several commonly-used qmail patches:

[Follow the patch details here]

Other patches:

smtp-auth + qmail-tls (starttls) + forcetls patch for qmail

I have put into a package the latest version of the following patches for netqmail-1.06. You may be interested to the combined patch I have put together here.

qmail-authentication

Provides cram-md5, login, plain authentication support.

qmail-tls

Implements SSL or TLS encrypted and authenticated SMTP between the MTAs and from MUA to MTA.
The SSLv3 connection was switched because of security reasons (thanks to Florian).

force-tls

Optionally gets qmail to require TLS before authentication to improve security.

Setting up your firewall with fail2ban

Fail2ban scans log files (e.g. /var/log/apache/error_log) and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc. Generally Fail2Ban is then used to update firewall rules to reject the IP addresses for a specified amount of time, although any arbitrary other action (e.g. sending an email) could also be configured. Out of the box Fail2Ban comes with filters for various services (apache, courier, ssh, etc).

I will show shortly how to install and configure fail2ban to ban malicious IPs, expecially those related to the qmail-dnsrbl patch. This will avoid to be banned ourselves by spamhaus, which is free up to 100.000 queries per day.

Sieve interpreter & Dovecot ManageSieve

The Pigeonhole project provides Sieve support as a plugin for Dovecot's Local Delivery Agent (LDA) and also for its LMTP service. The plugin implements a Sieve interpreter, which filters incoming messages using a script specified in the Sieve language. The Sieve script is provided by the user and, using that Sieve script, the user can customize how incoming messages are handled. Messages can be delivered to specific folders, forwarded, rejected, discarded, etc.

Dovecot Managesieve Server is a service used to manage a user's Sieve script collection.

Installing and configuring Spamassassin

SpamAssassin is a mature, widely-deployed open source project that serves as a mail filter to identify Spam. SpamAssassin uses a variety of mechanisms including header and text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases. SpamAssassin runs on a server, and filters spam before it reaches your mailbox.

Upgrading spamassassain to version 3.4.0

The release of version 3.4.0 was announced on Feb 11 2014. There are a few optional dependeces while dependency on the following Perl modules were dropped: Net::Ident, IP::Country::Fast and IP::Country. In addition, if you want to install the optional module Geo::IP you have to install GeoIP (here is the package link for slackware users) as well.

Here is how to update quickly:

qmailctl stop
spamdctl stop
perl -MCPAN -e shell
cpan> o conf prerequisites_policy ask
cpan> force notest install Geo::IP IO::Socket::IP Net::Patricia NetAddr::IP
cpan> force notest install  Mail::SpamAssassin Mail::SpamAssassin::Plugin::Razor2
cpan> quit
sa-update
spamdctl start
qmailctl start

ezmlm-web

ezmlm-web is a web interface for the administration of ezmlm mailing lists.

Merry Christmas and happy new... patch!

These days I had the opportunity to exchange ideas with a friend out there and take a look at his work and his customized jumbo patch. Some of the patches I came across have appeared to me very useful and I convinced myself to add some of them into my package.

The changelog is quite long this time! :)

Have fun!

Howto avoid being "cut off" by spamhaus.org

As you probably know spamhaus limits your smtp and DNS traffic (http://www.spamhaus.org/organization/dnsblusage/ for more info) and in case of big servers this can be a serious problem.

Luckily, Costel Balta sent me a solution to the problem that I'm going to copy below. In short, he suggests to dinamically create firewall rules via iptables (or better shorewall) to avoid connections from suspicious IPs in order to decrease the number of requests to the RBL lists of about 80%.

ipsets and swatch are also needed to manage iptables rules and scan your logs respectively.

A big thanks to Costel Balta for the following tutorial; this is not the first time that he posts an original idea.

Syndicate content