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Motivation

Many spammers crawl the web looking for email addresses. When they see an email address on a web page, they send spam to the address. Since 5.10 (2002,) WebBBS offers a *Blind Email* feature which hides posters' email addresses from visitors yet allows email be sent to them using the server's mail functionality. However, enabling *Blind Email* turns the server into an open mail-relay. Spammers may abuse the functionality to mass-spam your posters using YOUR server! 
 
Email-captcha plugin allows posters to safely post their email address on your forum. It hides an address and displays a "Show E-Mail" link. To reveal the address, a user must click on the link and solve a CAPTCHA. Bots won't be able to find the email address by simply scanning the HTML source of the pages and posters will get less spam. Be aware though that all known CAPTCHAs have been resolved by computer programs already. So targeting a specific site or software even a captcha won't prevent reading email addresses and later abuse them!

Nevertheless the email-captcha plugin does add some protection and makes it harder for blackhats to collect addresses from your site.

Files

• emailcaptcha.pl
• README_EC

Requirements

This plugin requires Authen::Captcha. If, however, your ISP doesn't have the module installed on your server, simply upload the appropriate files to your server space. For the details, ask at Tetra-Team's discussion board.

To install this plugin

• Upload emailcaptcha.pl to the folder where your bbs core script files reside
• In section (3) of those _config.pl files (for public access) that you want to use the plugin, add:
  

  require 'emailcaptcha.pl'; 

Configuration (optional)

• $captcha_num_of_characters = 6;
  Number of characters to use for the captcha
• $captcha_char_width = 65;
  $captcha_char_height = 60;
  Width and height for each character of the captcha[/list]

Notes

• For Tetra-WebBBS 5.22 and later versions only.
• Visually impaired users may have difficulty in solving visual CAPTCHA. Consider your audience before using this plugin.
• As with the other webbbs scripts, you need only one copy of the emailcaptcha.pl for all your boards.