Summary
Preventing non-human interaction (NHI) during email signup and confirmation requires a multi-layered approach combining various techniques and technologies. These include: employing real-time blocklists (RBLs) and tools like Spamhaus to block malicious IPs; utilizing services like reCAPTCHA, Akismet, and Cloudflare's Bot Management to analyze behavior and filter out bots; implementing honeypot fields, email validation, and MFA; using confirmed opt-in (COI) processes and Javascript challenges; progressively profiling users and employing custom fields to gather more information; implementing email authentication protocols (SPF, DKIM, DMARC); obscuring email addresses to prevent harvesting; and monitoring for suspicious signup patterns and behavior. The goal is to create a robust system that distinguishes between legitimate human users and automated bots.
Key findings
- IP Blocking: Using RBLs and services like Spamhaus to block signups from known malicious IP addresses effectively reduces bot activity.
- Behavioral Analysis: reCAPTCHA, Cloudflare Bot Management, and Imperva leverage behavioral analysis and adaptive challenges to differentiate between humans and bots.
- Honeypots and Hidden Fields: Implementing honeypot fields and hidden fields helps identify bots that automatically fill out all form fields.
- Email Validation & Verification: Robust email validation and verification services remove invalid, disposable, or risky email addresses, preventing bot signups.
- Multi-Factor Authentication: Including MFA in the COI process adds an extra layer of security, verifying user identity through multiple channels.
- Confirmed Opt-In (COI): Implementing COI ensures that users explicitly consent to receiving emails, reducing the likelihood of bot-generated signups.
- JavaScript Challenges: Employing Javascript challenges deters bots that cannot execute Javascript code.
- Progressive Profiling & Custom Fields: Progressive profiling and custom fields gather more information, making it harder for bots to mimic real users.
- Email Authentication: Implementing SPF, DKIM, and DMARC helps prevent email spoofing, ensuring secure delivery of confirmation emails.
- Pattern Monitoring: Monitoring signup patterns, such as high volume from the same IP or similar email addresses, can identify bot activity.
Key considerations
- User Experience (UX): Balancing security measures with UX is crucial. Overly aggressive measures can deter legitimate users.
- False Positives: Some techniques can generate false positives, incorrectly identifying legitimate users as bots. Monitoring and adjustments are essential.
- Evolving Bot Tactics: Bot technology continuously evolves, requiring ongoing adaptation of security measures.
- Resource Intensity: Real-time monitoring and integration with third-party services can be resource-intensive. Optimization is important.
- Accessibility Compliance: Ensure bot prevention mechanisms do not negatively impact accessibility for users with disabilities.
- Privacy Regulations: Comply with privacy regulations when collecting and analyzing user behavior data.
- Third-Party Costs: Integrating with third-party services like Akismet, StopForumSpam, and email verification tools may incur costs.
What email marketers say
11 marketer opinions
Preventing non-human interaction (NHI) during email signup and confirmation involves several layers of defense. Techniques include multi-factor authentication (MFA), honeypot fields, robust email validation, email verification services, confirmed opt-in (COI) processes, Javascript challenges, progressive profiling, custom fields, and email authentication protocols (SPF, DKIM, DMARC). These methods collectively aim to distinguish legitimate users from bots by requiring human interaction, verifying email validity, and analyzing behavior.
Key opinions
- MFA for COI: Including multi-factor authentication (MFA) in the confirmed opt-in (COI) email adds an extra layer of security by requiring users to verify their identity through multiple channels.
- Honeypot Fields: Honeypot fields, hidden from human users, can detect bots that automatically fill out all form fields.
- Email Validation: Robust email validation tools and services help ensure that only valid and legitimate email addresses are accepted during signup.
- Cloudflare Bot Management: Cloudflare bot management can be used to challenge requests and identify patterns of bots. This can be used to protect signup forms from bots that may not otherwise be spotted
- Confirmed Opt-In: Confirmed opt-in (COI) processes ensure that users explicitly consent to receiving emails, reducing the likelihood of bot-generated signups.
- JavaScript Challenges: JavaScript challenges require users to execute JavaScript code, which bots may not be able to do, deterring automated signups.
- Progressive Profiling: Progressive profiling makes it harder for bots to mimic real users and get through forms
- Custom Fields: Using Custom fields allows legitimate users to provide more specific answers making bots less likely to pass checks
- Email Authentication Protocols: Email authentication protocols (SPF, DKIM, DMARC) prevent email spoofing and ensure that confirmation emails are delivered securely to legitimate recipients.
Key considerations
- User Experience: While implementing security measures is crucial, it's essential to balance security with user experience. Overly aggressive security measures can deter legitimate users.
- False Positives: Some security measures may generate false positives, incorrectly identifying legitimate users as bots. It's important to monitor and adjust security settings to minimize false positives.
- Evolving Bot Technology: Bot technology is constantly evolving, so it's essential to stay updated on the latest bot techniques and adapt security measures accordingly.
- Integration: Ensure that the selected security measures integrate seamlessly with your existing signup process and email marketing platform.
- Compliance: Comply with privacy regulations and obtain explicit consent from users before collecting and using their data. In addition, some of these techniques, such as captchas, may not be compliant with accessibility requirements.
Marketer view
Email marketer from LinkedIn details progressively profiling users by requesting additional information over time. This makes it harder for bots to mimic human behavior and provides more data points to identify suspicious activity.
27 Dec 2023 - LinkedIn
Marketer view
Email marketer from MailerCheck shares that Implementing a confirmed opt-in (COI) process requires users to click a confirmation link in an email before being added to your mailing list. This helps ensure that the user is a real person and that they actually want to receive your emails.
1 Jun 2023 - MailerCheck
What the experts say
4 expert opinions
Preventing non-human interaction (NHI) during email signup and confirmation involves a combination of techniques focused on identifying and blocking suspicious activity. This includes using real-time blocklists (RBLs) to check IP addresses against known spammers, monitoring for suspicious signup patterns (high volume, similar email addresses), employing JavaScript requirements and bot checks, and even obscuring email addresses on websites to prevent harvesting. The goal is to layer defenses and make it difficult for bots to automate the signup process.
Key opinions
- IP Blocklists: Real-time blocklists (RBLs) help identify and block known spammers by checking IP addresses during signup.
- Pattern Monitoring: Monitoring for suspicious signup patterns (volume, email similarity) can flag potential bot activity.
- JavaScript and Bot Checks: Implementing JavaScript requirements and soft bot checks on landing pages adds a layer of verification against automated signups.
- Email Obfuscation: Obscuring email addresses on websites reduces harvesting and, though indirect, protects against bot-driven spam campaigns.
- Spamhaus IP Blocking: Declining signups from IPs listed on Spamhaus blocklist helps to prevent automated bot signups.
- Address Verification: Verifying email addresses with services helps ensure that valid and legitimate email addresses are used during signup.
Key considerations
- False Positives: Aggressive blocking can lead to false positives, impacting legitimate users. Regular monitoring and adjustments are needed.
- Resource Intensive: Real-time monitoring and checking against blocklists can be resource-intensive. Optimize for performance.
- Evolving Tactics: Bots and spammers continuously evolve their tactics. A layered approach is necessary to stay ahead.
- User Experience Impact: JavaScript requirements and CAPTCHAs can negatively impact user experience. Use them judiciously.
- Accessibility: Ensure bot prevention mechanisms do not negatively impact accessibility for users with disabilities.
Expert view
Expert from Spam Resource explains that Monitoring for suspicious signup patterns, such as a high volume of signups from the same IP range or using similar email addresses, can indicate bot activity.
15 Aug 2021 - Spam Resource
Expert view
Expert from Word to the Wise responds that bots harvest addresses to find valid email addresses for spamming. One method to avoid this is obscuring email addresses on a website. This may not directly prevent NHI on signup but reduces the email addresses being obtained to use for spamming.
29 Mar 2022 - Word to the Wise
What the documentation says
5 technical articles
Preventing non-human interaction (NHI) during email signup and confirmation involves employing various techniques and services that leverage risk analysis, machine learning, and behavioral analysis. reCAPTCHA uses behavior analysis and adaptive challenges, OWASP recommends rate limiting and CAPTCHAs, Akismet analyzes form submissions for spam-like content, StopForumSpam checks against a database of known spammers, and Imperva utilizes behavioral analysis to identify anomalies in user behavior. These methods aim to distinguish between legitimate human users and automated bots by analyzing various data points and behaviors.
Key findings
- reCAPTCHA Analysis: Google reCAPTCHA uses an advanced risk analysis engine and adaptive challenges to differentiate between humans and bots.
- Rate Limiting: OWASP recommends rate limiting to restrict the number of requests a user can make, preventing bots from overwhelming the system.
- CAPTCHAs: Implementing CAPTCHAs is a common method to verify that a user is human before proceeding with signup.
- Akismet API: Akismet's API analyzes form submissions for spam-like content, filtering out potentially malicious interactions.
- StopForumSpam Integration: Integrating with StopForumSpam allows checking IP and email addresses against a database of known spammers.
- Behavioral Analysis: Imperva utilizes behavioral analysis to detect anomalies in user behavior, such as mouse movements and keystroke dynamics.
Key considerations
- User Experience: While these methods are effective, it's important to consider the impact on user experience, as overly aggressive measures can deter legitimate users.
- False Positives: Some techniques, such as CAPTCHAs and behavioral analysis, may generate false positives, requiring careful configuration and monitoring.
- Maintenance: Maintaining and updating these systems is important to ensure they remain effective against evolving bot tactics.
- Integration Costs: Integrating with third-party services such as Akismet and StopForumSpam may incur costs and require ongoing maintenance.
- Privacy Implications: Collecting and analyzing user behavior data has privacy implications, requiring compliance with relevant regulations.
Technical article
Documentation from StopForumSpam details that you can integrate with StopForumSpam's database to check if an IP address or email address has been associated with spam activity. This helps identify and block known spammers and bots from signing up.
18 Sep 2023 - StopForumSpam
Technical article
Documentation from Akismet explains using Akismet's API, you can analyze form submissions for spam-like content, and identify potentially malicious interactions. Akismet uses machine learning to recognize patterns and characteristics of spam, helping you filter out non-human signups.
22 Feb 2022 - Akismet
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