Are auto warming/deliverability improvement services for email marketing sketchy?
Michael Ko
Co-founder & CEO, Suped
Published 2 Jun 2025
Updated 18 Aug 2025
8 min read
The idea of effortlessly boosting your email deliverability with an automated service sounds appealing, especially when you're facing inbox placement challenges. These email warming tools promise to simulate positive engagement, thereby improving your sender reputation. It's easy to see why marketers might be drawn to them as a quick fix.
However, the question often arises: are these auto warming or deliverability improvement services genuinely effective, or are they, as some suspect, a bit sketchy? Many in the email community express strong reservations, viewing these services as a risky shortcut.
This article will delve into how these services operate, why they might be problematic, and what truly effective strategies you should focus on to improve your email deliverability and sender reputation.
Understanding email warming
Email warming, whether for an IP address or a domain, is the process of gradually increasing your email sending volume over time. This helps Internet Service Providers (ISPs) like Google and Yahoo (or any mailbox provider) recognize you as a legitimate sender. They observe your sending patterns, email content, and most importantly, recipient engagement to build a sender reputation for your email sending infrastructure.
A good sender reputation is crucial because it directly influences whether your emails land in the inbox or the spam folder. Without proper warming, a sudden high volume of emails from a new or cold IP/domain can trigger spam filters, leading to poor inbox placement. This is why email warming is necessary before sending cold emails from a new domain, for example.
The core principle is to demonstrate consistent, positive sending behavior to ISPs. This means sending to engaged recipients, maintaining low bounce rates, avoiding spam complaints, and seeing healthy open and click-through rates. When performed correctly, warming can boost email deliverability and help establish a strong domain and IP reputation.
This involves carefully managing your sending volume and gradually expanding your recipient base. For a deeper understanding of IP warming services and their effectiveness, it's important to differentiate between legitimate practices and those that merely simulate engagement.
How automated email warming services operate
Automated warming services typically work by enrolling your email address into a network of other users. These users' inboxes then exchange emails with yours, automatically opening, clicking, and sometimes even replying to emails. The goal is to mimic natural, positive engagement to artificially inflate your sender reputation. Providers of these services often claim they can rapidly improve your deliverability by generating a high volume of positive interactions.
This approach aims to trick ISPs into seeing your domain or IP as trustworthy, even if your actual sending practices or list quality don't warrant it. The services essentially create a fabricated history of good behavior, hoping that this facade will lead to better inbox placement for your legitimate marketing or transactional emails. This is particularly tempting for those engaged in cold outreach or with new domains.
While the concept seems logical on the surface (more engagement equals better reputation), the artificial nature of these interactions is their fundamental flaw. These aren't real people engaging with your content because they find it valuable, but rather automated systems designed to manipulate metrics. This distinction is critical, as ISPs are increasingly sophisticated in detecting such patterns.
Manual email warming
Process: Gradually send emails to highly engaged segments of your list.
Engagement: Relies on genuine opens, clicks, and replies from real recipients.
Control: You have full control over content, audience, and sending volume.
Timeframe: Can take several weeks or months for full reputation building.
The inherent sketchiness of auto-warming services
The primary reason these services are considered sketchy is that they attempt to manipulate reputation signals rather than build them authentically. ISPs use sophisticated algorithms to detect unusual patterns and differentiate between genuine and fabricated engagement. For example, if an email from a new sender receives an unusually high rate of opens and clicks from a diverse set of IP addresses that don't align with normal user behavior, it can raise a red flag. As one expert from Email Geeksnoted in a discussion, there's little chance Gmail won't know what's going on.
The consequences of being caught using such services can be severe. Your domain or IP address might be flagged, leading to a damaged sender reputation. This can result in your emails being consistently delivered to spam folders, or worse, being outright blocked by ISPs. Once your reputation takes a hit, it can be a lengthy and challenging process to recover your email deliverability, impacting all your future email marketing efforts.
Furthermore, engaging with these services can expose you to security risks. You are essentially allowing third-party services access to your email accounts or sending infrastructure, which could be exploited. The artificial engagement they generate might also include interactions with spam traps or other toxic addresses, further harming your deliverability and possibly getting your domain placed on an email blacklist or blocklist.
Risks of automated warming
Detection by ISPs: Sophisticated algorithms can easily identify automated, unnatural engagement patterns.
Reputation Damage: Getting caught can severely damage your sender reputation, leading to long-term deliverability issues.
Blocklisting: Your IP or domain may end up on a blacklist or blocklist, preventing emails from reaching inboxes.
Security Concerns: Granting access to third-party services can pose significant security risks to your email accounts.
Effective strategies for deliverability improvement
Instead of relying on questionable automated services, focus on building a strong sender reputation through legitimate and sustainable practices. The foundation of good deliverability lies in sending relevant, valuable content to an engaged audience. This starts with proper list hygiene, ensuring your email list is clean and free of invalid or unengaged addresses. Regularly cleaning your list reduces bounces and spam trap hits, which are critical for maintaining a positive reputation.
Implement robust email authentication protocols such as SPF, DKIM, and DMARC. These technical configurations prove that your emails are legitimately from your domain and haven't been tampered with. ISPs rely heavily on these records to verify sender identity and prevent phishing and spoofing, making them a cornerstone of modern email security and deliverability. You can monitor your DMARC reports using a service like Suped to ensure these protocols are working correctly.
Another crucial aspect is consistent monitoring of your email campaigns. Pay close attention to your open rates, click-through rates, bounce rates, and crucially, spam complaint rates. Tools like Google Postmaster Tools and other analytics dashboards provide valuable insights into how your emails are performing from an ISP perspective. Addressing any negative trends swiftly can prevent them from escalating into major deliverability issues. For more detailed insights into email deliverability best practices, a comprehensive guide can offer further steps.
Furthermore, a legitimate email warmup involves starting with small batches of highly engaged subscribers and gradually expanding your sending volume based on positive engagement metrics. This organic growth of your sending volume, coupled with quality content and proper technical setup, is the most reliable way to achieve and maintain excellent email deliverability and avoid being flagged or added to a blocklist (or blacklist).
Views from the trenches
Best practices
Maintain a clean email list by regularly removing unengaged subscribers and invalid addresses.
Consistently send valuable, relevant content to encourage genuine recipient engagement.
Implement strong email authentication: SPF, DKIM, and DMARC are non-negotiable for deliverability.
Monitor your sender reputation metrics proactively using tools like Google Postmaster Tools.
Gradually increase your sending volume with real user engagement to build trust with ISPs.
Common pitfalls
Using automated email warming services that simulate engagement, which ISPs can easily detect.
Sending to old, uncleaned lists that contain spam traps or inactive email addresses.
Ignoring email authentication settings, leaving your domain vulnerable to spoofing.
Failing to monitor deliverability metrics, missing early warning signs of reputation issues.
Attempting to send high volumes of emails from a new domain or IP without proper warming.
Expert tips
Focus on segmenting your audience and tailoring content to maximize genuine interaction.
Prioritize recipient experience: make it easy to unsubscribe and avoid deceptive practices.
Invest in ongoing education about deliverability best practices, as ISP rules evolve.
Leverage DMARC reports to identify and address authentication failures quickly.
Consider engaging with a deliverability consultant for complex or persistent issues.
Marketer view
Marketer from Email Geeks says that automated warming services are a bit sketchy and primarily appear in outreach circles as a way to warm a domain before sending.
2021-06-15 - Email Geeks
Marketer view
Marketer from Email Geeks says that automated warming services are 100% sketchy.
2021-06-15 - Email Geeks
The path to genuine deliverability
While auto warming and deliverability improvement services might offer a tempting shortcut, they often prove to be more detrimental than beneficial in the long run. Their reliance on artificial engagement risks detection by sophisticated ISP algorithms, potentially leading to severe penalties like blacklisting (or blocklisting) and damaged sender reputation.
True email deliverability is built on a foundation of authentic engagement, meticulous list hygiene, robust email authentication, and continuous performance monitoring. Investing in these legitimate practices ensures sustainable success and a healthy sender reputation, allowing your emails to consistently reach the inbox.
Avoid the sketchy shortcuts and embrace the proven methods. Your email program, and your recipients, will thank you for it.
Google and 
Yahoo (or any mailbox provider) recognize you as a legitimate sender. They observe your sending patterns, email content, and most importantly, recipient engagement to build a sender reputation for your email sending infrastructure.
Gmail won't know what's going on.
Suped to ensure these protocols are working correctly.
