Dr. Dobb's is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.


Channels ▼
RSS

Spam-Proofing Your Qmail Server

By Chris Woodard, April 01, 2003

The Mail Transfer Agent (MTA) qmail is a popular alternative to Sendmail. Qmail has a number of features that make it easy to spam-proof. Qmail separates the functions of SMTP transaction capture and delivery queuing into different processes. It does this in such a way that external programs can be invoked to intercept messages on their way from the SMTP daemon to the delivery queuing daemon and filter out those that meet the organization's criteria for spam (including originating IP, keywords in the title or message body, or Bayesian word distribution). This can help reduce the amount of incoming spam. Qmail also has a feature that lets an administrator keep spammers from using the mail server as a mail relay to hide the origin of the spam.
Listing 1 xinetd configuration for qmail smtpd that invokes tcpd as a wrapper around qmail-smtpd 

 # default: on
 # description: smtp for qmail.
 service smtp
 {
 disable = no
 flags = REUSE NAMEINARGS
 socket_type = stream
 protocol = tcp
 wait = no
 user = qmaild
 server = /usr/sbin/tcpd
 server_args = /var/qmail/bin/tcp-env _R \
 /var/qmail/bin/qmail-smtpd
 }

 (A similar configuration file can be used for qmail-pop3d, which is 
 qmail's built-in POP3 daemon.)



Previous 1 2 3 4 5 6 7 Next

Related Reading

News

Commentary

Slideshow

Video

Most Popular

More Insights

White Papers

More >>

Reports

More >>

Webcasts

More >>
INFO-LINK




Currently we allow the following HTML tags in comments:

Single tags

These tags can be used alone and don't need an ending tag.

<br> Defines a single line break

<hr> Defines a horizontal line

Matching tags

These require an ending tag - e.g. <i>italic text</i>

<a> Defines an anchor

<b> Defines bold text

<big> Defines big text

<blockquote> Defines a long quotation

<caption> Defines a table caption

<cite> Defines a citation

<code> Defines computer code text

<em> Defines emphasized text

<fieldset> Defines a border around elements in a form

<h1> This is heading 1

<h2> This is heading 2

<h3> This is heading 3

<h4> This is heading 4

<h5> This is heading 5

<h6> This is heading 6

<i> Defines italic text

<p> Defines a paragraph

<pre> Defines preformatted text

<q> Defines a short quotation

<samp> Defines sample computer code text

<small> Defines small text

<span> Defines a section in a document

<s> Defines strikethrough text

<strike> Defines strikethrough text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

Dr. Dobb's encourages readers to engage in spirited, healthy debate, including taking us to task. However, Dr. Dobb's moderates all comments posted to our site, and reserves the right to modify or remove any content that it determines to be derogatory, offensive, inflammatory, vulgar, irrelevant/off-topic, racist or obvious marketing or spam. Dr. Dobb's further reserves the right to disable the profile of any commenter participating in said activities.

 
Disqus Tips To upload an avatar photo, first complete your Disqus profile. | View the list of supported HTML tags you can use to style comments. | Please read our commenting policy.
 

Recent Articles

Most Popular

Stories Blogs

Upcoming Events



Most Recent Premium Content

Digital Issues