Identifying and preventing bot submissions outside of double opt-in requires a multifaceted approach, as no single method guarantees complete protection. Experts, marketers, and documentation emphasize combining various techniques to create a robust defense. Key strategies include analyzing user behavior (e.g., mouse movements, form completion speed), using honeypot fields, implementing JavaScript challenges, leveraging reCAPTCHA v3 scores, blacklisting IPs, rate limiting submissions, detecting anomalies in signup patterns, utilizing spam databases for email validation, employing confirmation pages, and analyzing submission patterns. Technical documentation highlights the importance of analyzing request attributes, input validation, and carefully adjusting security thresholds.