What are email marketing experts' opinions on using ZeroBounce for email list cleaning?
Michael Ko
Co-founder & CEO, Suped
Published 16 Jul 2025
Updated 13 Oct 2025
8 min read
Maintaining a clean email list is fundamental for effective email marketing and achieving high deliverability. In today's email landscape, sending messages to invalid, inactive, or risky addresses can severely harm your sender reputation, leading to higher bounce rates and even getting your domain or IP address on a blacklist. This is where email list cleaning services, like ZeroBounce, come into play.
These services promise to scrub your lists, remove problematic contacts, and ultimately boost your campaign performance. But with so many options available, it is important to understand what the experts in the field think about specific tools. I have gathered insights from various email marketing professionals regarding their opinions and experiences with ZeroBounce, a prominent name in email verification.
Understanding the purpose of email validation services
Email validation services are designed to identify and remove problematic email addresses from your mailing lists. The goal is to ensure your messages reach legitimate inboxes, thereby improving email deliverability, engagement rates, and the overall return on investment of your email campaigns. Sending emails to invalid addresses results in hard bounces, which signal to Internet Service Providers (ISPs) that your sending practices are poor, negatively impacting your sender reputation.
These services typically check for various issues, including syntax errors, non-existent domains, deactivated accounts, and known spam traps. By removing these risky contacts, marketers can reduce their bounce rates, avoid blocklisting, and ultimately ensure their emails land in the inbox.
Employing an email verification service is a crucial step in maintaining a healthy email database. It is particularly useful for cleaning older lists, validating new sign-ups in real-time, or when dealing with data acquired from third-party sources. The long-term benefits include improved campaign performance and a stronger sending reputation.
ZeroBounce: a closer look
ZeroBounce is widely recognized in the email marketing industry as a leading email verification and list cleaning service. Many marketers initially view it as a robust solution for ensuring clean and accurate email lists. It offers features like bulk email validation, real-time API verification, and additional services such as email scoring and abuse monitoring. The company often highlights its high accuracy rates and user-friendly interface as key benefits.
For many, the promise of reducing bounce rates and improving deliverability makes services like ZeroBounce seem like a necessary tool. They aim to catch problematic addresses before they impact your email campaigns, helping to maintain a healthier audience and boost sender reputation. This proactive approach can prevent issues that lead to your emails being marked as spam or your domain getting added to a blacklist (or blocklist).
ZeroBounce typically categorizes emails into statuses like valid, invalid, catch-all, unknown, spam trap, and abuse. This categorization allows marketers to make informed decisions about which emails to keep or discard. For example, knowing if an email is a catch-all can inform whether it is worth the risk of sending to, as these can sometimes be difficult to verify with 100% certainty.
Typical validation categories
Valid: These are verified to be real and deliverable.
Invalid: Emails that do not exist or have syntax errors.
Spam trap: Addresses used to catch spammers, best to remove immediately.
Abuse: Accounts associated with complainers or problematic users.
Concerns and varying perspectives
Despite widespread use and generally positive reviews in public forums, some email marketing experts express significant reservations about ZeroBounce. While many users report solid accuracy and a reduction in bounce rates, a few seasoned professionals in the deliverability space have had experiences that led them to cease doing business with the company entirely. These strong opinions highlight that even a popular service might not be the right fit for everyone or could have underlying issues not immediately apparent to the average user.
One prominent expert expressed a firm stance, stating they would never recommend ZeroBounce again. While the specific reasons for such a strong dismissal are often not publicly detailed due to contractual obligations or privacy, this sentiment suggests issues beyond simple technical performance or accuracy. It might stem from factors like customer service, ethical concerns, data handling, or even a perceived lack of transparency that led to a breakdown of trust. In fact, there was a notable incident where ZeroBounce spammed email marketers on Twitter, which certainly contributed to negative perceptions among some professionals.
The location of an email company can sometimes factor into its reputation. Historically, some email companies operating out of South Florida have faced scrutiny for business practices that lean towards spamming. While this does not imply any specific wrongdoing by ZeroBounce, some experts remain cautious, given past patterns in the region. This context suggests a broader industry awareness of geographical reputation influencing perceptions of trustworthiness in the email space. The history of email companies in Florida can be quite complex, with some individuals connected to previous spamming activities. This historical background occasionally casts a shadow on new players in the region, prompting heightened scrutiny from seasoned industry veterans.
General perception
ZeroBounce is generally seen as a leader in email verification, known for its strong accuracy and user-friendly interface. Many marketers report positive outcomes, especially in reducing hard bounces and improving immediate campaign metrics. This widespread positive feedback contributes to its high market visibility and adoption among businesses looking for a straightforward email cleaning solution.
Beyond the tool: holistic list hygiene
A critical point raised by experts is that relying solely on an external tool like ZeroBounce for email list hygiene indicates deeper underlying issues. If you frequently need to clean your list, it might point to fundamental problems in your lead acquisition process or list management practices. This includes not having proper validation on your forms, failing to rate-limit sign-ups, or sourcing data from untrustworthy channels.
Effective email marketing hinges on proactive list management, not just reactive cleaning. This means implementing best practices from the moment a subscriber joins your list. Double opt-in, for instance, confirms that the email address is valid and the user genuinely wants to receive your communications, significantly reducing the chances of adding bad data. Regularly removing inactive subscribers also keeps your list healthy and engaged, protecting your sender reputation.
While email verification services can play a role, they are not a substitute for robust internal hygiene protocols. Tools like ZeroBounce can certainly help with immediate clean-ups or one-time list validations. However, a sustainable strategy involves continuous monitoring, engagement segmentation, and prompt removal of unengaged or bouncing addresses. This holistic approach ensures that your email list remains a valuable asset for your marketing efforts.
Reactive approach
Reliance on external tools: Primarily uses services like ZeroBounce for periodic clean-ups after issues arise.
High bounce rates: Experiences frequent hard bounces before cleaning.
Potential blocklisting: Higher risk of hitting spam traps and getting IPs blacklisted.
Lower bounce rates: Prevents invalid emails from entering the list in the first place.
Stronger sender reputation: Maintains a clean list, fostering trust with ISPs and improving deliverability rates.
Final thoughts on email list cleaning
The opinions on ZeroBounce among email marketing experts are mixed, reflecting varied experiences and philosophies on email list hygiene. While many marketers find it a valuable tool for reducing bounce rates and improving deliverability, some seasoned professionals have encountered issues that lead them to advise against its use. These concerns often go beyond mere technical performance, touching upon broader business practices or even the inherent limitations of relying heavily on third-party verification services.
Ultimately, while ZeroBounce can certainly assist with email list cleaning, it is not a silver bullet. The consensus among experts points to the importance of a comprehensive approach to email list health. This means prioritizing proactive list hygiene from the outset, including stringent sign-up processes, regular engagement analysis, and timely removal of unengaged subscribers. By combining smart internal practices with judicious use of verification tools, marketers can achieve and maintain optimal deliverability for their campaigns.
Views from the trenches
Best practices
Implement a double opt-in process for all new subscribers to ensure consent and validity.
Regularly monitor your email campaign metrics, especially bounce rates and engagement levels.
Segment your list based on engagement and consider suppressing or removing inactive subscribers.
Validate email addresses at the point of entry (form submission) to prevent bad data from entering your list.
Educate your team on email list hygiene best practices to foster a culture of data quality.
Common pitfalls
Relying solely on one-time list cleaning services without ongoing hygiene practices.
Failing to implement proper spam checks or rate limiting on signup forms, leading to bot submissions.
Purchasing email lists, which often contain invalid, outdated, or spam trap addresses.
Not segmenting or removing unengaged subscribers, harming sender reputation over time.
Ignoring soft bounces, which can escalate into hard bounces and deliverability issues.
Expert tips
Consider a multi-layered approach to email validation, including both real-time checks and periodic bulk cleaning.
Beyond validation, focus on overall subscriber engagement to keep your list healthy and responsive.
Invest in tools that provide detailed insights into email health, not just a simple valid/invalid status.
Regularly review your email sending infrastructure and ensure all authentication protocols are correctly configured.
Stay informed about ISP requirements and updates, as these often influence best practices for list hygiene.
Expert view
Expert from Email Geeks says they would not do business with ZeroBounce again and would not recommend them to others.
2024-12-12 - Email Geeks
Marketer view
Marketer from Email Geeks says they have used ZeroBounce in previous roles without obvious downsides and is interested in what specifically went wrong for others.
ZeroBounce is generally seen as a leader in email verification, known for its strong accuracy and user-friendly interface. Many marketers report positive outcomes, especially in reducing hard bounces and improving immediate campaign metrics. This widespread positive feedback contributes to its high market visibility and adoption among businesses looking for a straightforward email cleaning solution.
