Spam Filtering for Webpages-Computing Services - Carnegie Mellon University

Spam Filtering for Webpages

The "mailto:" Tag

Spam Robots or Spiders "crawl" the internet searching for "mailto:" tags. To create a clickable "mailto:" hyperlink that is mostly spam resistant, use the following JavaScript on your web pages.

<!-- Begin
user = "myusername";
site = "";
document.write('<a href=\"mailto:' + user + '@' + site + '\">');
document.write('Email Our Department' + '</a>');
// End -->

Steps to create a clickable "mailto:" hyperlink:

  1. Copy and insert the above JavaScript into your HTML source code at the mailto: insertion point.
    Note: Some HTML authoring tools may require you to use an automated tool for inserting the JavaScript (e.g., Insert > Script Object in Dreamweaver).
  2. Edit the script to include the user name and mail host.

    For example, suppose email should be sent to Within the script, the lines that read:
    user = "myusername";
    site = "";

    Change to:
    user = "juser";
    site = "";
  3. Save your HTML file. The JavaScript will generate a clickable link that reads "Email Our Department."

Spam-Resistant List of Email Addresses

If you must maintain a web page of email addresses, restrict it to one page. You can limit the number of SpamBots from indexing the page with the following meta tag:

"meta name="Robots" content="noindex,nofollow"

Most SearchBots, SpamBots & Web crawlers ignore pages with this tag.

Last Updated: 10/14/10