One technique spammers use to send unsolicited messages is exploiting the contact forms of websites, often for advertising or malicious purposes.
When a website's contact form is used for spam submissions, it can face issues such as overloaded email inboxes, decreased deliverability of legitimate messages, and potentially face security risks.
To prevent this, here are some useful measures you can take to protect your website's contact form:
Implement reCAPTCHA - This well-known tool developed by Google helps identify and block suspicious activity. Opt for reCAPTCHA v3 whenever possible, as it doesn't require user interaction most of the time. If you encounter compatibility issues or legitimate users are being blocked, use reCAPTCHA v2.
Custom captchas - As an alternative, you can add your own version by adding a mandatory random question. Make sure to rotate the questions on a regular basis
Install antispam plugins - If your website is built using WordPress, there are both free and paid solutions like Akismet, Antispam Bee, CleanTalk, and others that offer advanced spam filtering and protection
Enable a honeypot - Some WordPress plugins allow you to create a hidden field that flags submissions as it will only be filled in by spambots. This option does not create false positives, as it is invisible to humans
Disable autoresponders - Avoid sending automated confirmation emails upon form submission. While this doesn't directly prevent spam, it reduces the potential for information harvesting, will save you resources and protect your email reputation. Instead, you can use a confirmation page after the submission to acknowledge it
Some additional considerations are to check for plugin compatibility, regularly monitor your antispam tools to avoid legitimate inquiries being flagged as spam and keep your scripts and plugins up to date.
Spammers constantly develop new techniques, so a multi-layered approach is crucial for to keep your contact forms protected. Feel free to use a combination of the above strategies, based on your website's specific needs and resources. This way, you can significantly reduce contact form spam and keep an efficient communication with your audience.