How to spamproof a mailto link

Question

When adding a mailto link to a website, how can I protect it from being harvested by spammers? Are there specific obfuscation or alternative techniques that are easy to implement while still user-friendly?

Answer 1

Protecting email addresses in mailto links from being harvested by spammers is crucial for maintaining privacy and reducing unsolicited emails. Here are several techniques to consider:

1. JavaScript Obfuscation: Utilize JavaScript to dynamically generate the email address, making it less accessible to basic bots that don't execute scripts. For example, you can split the email address and reconstruct it using JavaScript:

   <script type="text/javascript"> // <![CDATA[ var user = 'example'; var domain = 'domain.com'; document.write('<a href="mailto:' + user + '@' + domain + '">' + user + '@' + domain + '</a>'); // ]]> </script>

   This method ensures that the email address is not directly present in the HTML source, making it harder for bots to detect.

2. Contact Forms: Instead of displaying an email address, provide a contact form on your website. This approach keeps your email address hidden from bots entirely. Ensure the form includes CAPTCHA or other anti-spam measures to prevent automated submissions.

3. Email Address Obfuscation: Alter the email address format to make it less recognizable to bots while remaining understandable to human users. For instance, replace "@" with "[at]" and "." with "[dot]":

   example[at]domain[dot]com

   While this method offers minimal protection, it can deter less sophisticated bots. However, advanced bots may still parse these patterns.

4. Email Address Encoding: Encode the email address using HTML character entities to make it less readable by bots that scan for plain text addresses:

   <a href="mailto:&#101;&#120;&#97;&#109;&#112;&#108;&#101;&#64;&#100;&#111;&#109;&#97;&#105;&#110;&#46;&#99;&#111;&#109;">Email Us</a>

   This method can deter simple bots but may not be effective against more advanced ones.

5. CAPTCHA Protection: If you opt for a contact form, implementing CAPTCHA can prevent automated bots from submitting spam through the form. This ensures that only human users can send messages via your website.

6. Email Address Images: Display your email address as an image rather than text. This prevents bots from reading it, though it may inconvenience users who cannot copy and paste the address. Additionally, ensure the image has appropriate alt text for accessibility.

While no method guarantees complete protection against email harvesting, combining these techniques can significantly reduce the likelihood of your email address being targeted by spammers. Regularly updating your anti-spam strategies and monitoring for new harvesting methods is also advisable.