Why are cold email senders difficult to help with deliverability issues?
Michael Ko
Co-founder & CEO, Suped
Published 5 Aug 2025
Updated 19 Aug 2025
8 min read
Dealing with deliverability issues for cold email senders can be one of the most challenging aspects of email security and deliverability. While many senders genuinely seek to improve their email delivery, those engaged in high-volume, unsolicited outreach often face systemic problems rooted in their fundamental approach. These issues are not just technical, but often stem from a deeply ingrained mindset that prioritizes scale over permission and engagement.
The inherent challenges of cold outreach
One of the primary difficulties lies in the nature of cold email itself. Unlike transactional or marketing emails sent to opted-in subscribers, cold emails are by definition unsolicited. This immediately places them under intense scrutiny from mailbox providers and spam filters like Gmail and Outlook. Their algorithms are designed to protect users from unwanted mail, and cold emails often exhibit patterns consistent with spam. This makes it a constant uphill battle to achieve good inbox placement, especially with the latest email provider updates.
Many cold emailers are also operating with a fundamental misunderstanding of sender reputation. They might believe that simply setting up SPF, DKIM, and DMARC is enough to ensure delivery. While these authentication protocols are crucial, they are merely the baseline. A strong sender reputation is built over time through consistent sending of wanted mail, low complaint rates, high engagement, and minimal bounces. Cold email campaigns, by their very nature, often struggle with these positive signals. When emails fail to land in the inbox, it's frequently due to a poor sender reputation.
The sheer volume of emails often sent in cold outreach is another major hurdle. Many cold emailers attempt to send thousands of emails daily from a single domain or IP, which is a significant red flag for mailbox providers. This aggressive sending behavior can quickly lead to blocklisting (being added to an email blacklist), temporary throttling, or even permanent damage to the sender's domain reputation. Recovering from such damage is a lengthy and complex process, making it difficult to achieve stable deliverability for clients who insist on high-volume, unsegmented blasts.
Misaligned expectations and quick fixes
A common issue is the expectation of a quick fix for deeply rooted problems. Many cold email senders are looking for a silver bullet rather than a sustainable strategy. They might have already tried domain cycling (burning through domains and moving to new ones) or using purchased or scraped lists, both of which severely harm deliverability. When confronted with the need for fundamental changes to their sending practices, they often become resistant, as these changes might conflict with their immediate revenue goals.
This leads to a clash of perspectives. As deliverability specialists, we focus on long-term sender health, adherence to best practices, and building a positive reputation. Cold emailers, however, often prioritize immediate outreach volume and lead generation, sometimes at the expense of deliverability metrics. This misalignment makes it difficult to implement effective solutions, as the client may not see the value in slowing down or changing their approach when it seems to directly impact their perceived business model. They may want to find out how to handle deliverability issues with cold email, but not be open to fundamental changes.
The sender's perspective
Focus on immediate lead generation and sales. High volume is often seen as necessary for reaching targets. May view deliverability as a technical hurdle to bypass, rather than a trust indicator. Quick fixes are preferred over long-term strategic changes.
This constant search for a cheap fix, or a workaround that allows them to continue sending large volumes of unsolicited emails, often undermines any genuine effort to improve deliverability. It becomes a cycle of attempting to circumvent filters rather than building a legitimate sender reputation, making sustainable improvements elusive.
Technical debt and reputation damage
Cold emailers often neglect critical technical configurations beyond basic authentication. Many fail to implement DMARC properly or monitor their DMARC reports, missing crucial insights into their email authentication health. They might also overlook the importance of spam traps and maintain clean lists. This technical debt compounds their deliverability woes, leading to persistent issues that are hard to diagnose and fix without a complete overhaul.
The content of cold emails also frequently triggers spam filters. Aggressive sales language, excessive links, lack of personalization, and embedded tracking pixels can all contribute to emails landing in the spam folder or being outright blocked. Mailbox providers prioritize user experience, and anything that looks like unsolicited commercial email, regardless of technical setup, is likely to be flagged. This means even with perfect authentication, content issues can tank deliverability. For more on why your emails are going to spam, it is best to review current best practices.
Furthermore, a low engagement rate from recipients is a strong negative signal. When cold emails are rarely opened, clicked, or replied to, and frequently marked as spam or deleted without being read, it tells ISPs that the mail is unwanted. This behavioral feedback loop can cause significant and lasting damage to sender reputation, making it increasingly difficult to reach the inbox even for subsequent, more legitimate campaigns. Understanding email domain reputation is key.
Behavioral barriers to improvement
Perhaps the most significant challenge is the sender's unwillingness to adapt their strategy. When faced with advice to reduce volume, improve list quality, personalize content, or engage in domain warming, some cold emailers resist, often stating that these changes will hurt their business model. They may become defensive, viewing expert recommendations as an attack on their entire marketing approach. This makes it incredibly difficult to implement the necessary changes for long-term deliverability success. It is important to remember the deliverability challenges that come with this type of sending.
The temptation to simply restart with a new domain after being blocklisted (blacklisted) is strong for these senders. While it offers a temporary reprieve, it's a short-sighted approach that prevents the accumulation of positive sender history and ultimately leads to a cycle of repeated deliverability failures. Each new domain will eventually suffer the same fate if the underlying sending practices remain unchanged. It also means that their cold emails will likely impact warm email deliverability.
Ultimately, helping cold email senders requires a commitment from them to change their core approach. Without this commitment, efforts to improve deliverability often become futile, resembling a futile attempt to bail out a leaky boat without patching the holes. Our role is to provide the best practices and solutions, but the willingness to adopt them truly lies with the sender.
Views from the trenches
Best practices
Always begin with proper domain warming, gradually increasing volume over several weeks to build a positive sending history.
Segment your email lists carefully to ensure targeted messaging and higher relevance for recipients, reducing complaints.
Regularly clean your email lists to remove invalid addresses, hard bounces, and disengaged contacts, preventing spam traps.
Personalize your cold emails significantly to demonstrate genuine outreach rather than bulk messaging.
Ensure all technical authentication records like SPF, DKIM, and DMARC are correctly configured and monitored for issues.
Common pitfalls
Sending thousands of emails daily from a new or un-warmed domain, leading to immediate blocklisting or throttling.
Purchasing or scraping email lists, resulting in high bounce rates and hitting spam traps, damaging sender reputation.
Ignoring spam complaints and low engagement, which signals to mailbox providers that your emails are unwanted.
Focusing solely on volume rather than the quality of leads and the relevance of your email content.
Believing that simply adding authentication will bypass all deliverability issues, neglecting content and recipient behavior.
Expert tips
Implement a DMARC policy with reporting to gain visibility into authentication failures and potential abuse of your domain.
Use a dedicated sending domain for cold outreach to isolate its reputation from your primary business domain.
Monitor your domain's sender reputation through tools like
Google Postmaster Tools
to identify issues early.
Marketer view
Marketer from Email Geeks says they had a potential client sending 5,000 to 10,000 cold leads daily, who had already burned through one domain due to blocks and wanted help making it work. They described it as a 'dumpster fire' too complex to justify taking on.
2023-07-26 - Email Geeks
Marketer view
Marketer from Email Geeks says these types of clients are 'potential nightmares' rather than 'potential work,' which makes them thankful for rejecting such applications.
2023-07-26 - Email Geeks
Navigating cold email deliverability
Helping cold email senders with deliverability challenges is a complex endeavor, primarily due to the inherent nature of unsolicited email and the often-misaligned expectations of the senders themselves. The strategies that work for permission-based email marketing simply don't translate effectively to cold outreach without significant modifications.
Achieving consistent inbox placement for cold emails requires more than just technical setup, it demands a fundamental shift in approach. This includes meticulous list quality, conservative sending volumes, highly personalized content, and a willingness to build sender reputation gradually rather than aggressively. Without these foundational changes, even the most skilled deliverability expert will struggle to make a lasting impact.
Ultimately, the success of any deliverability intervention hinges on the sender's commitment to adopting sustainable and ethical sending practices. While the pursuit of new leads is vital for business growth, it should not come at the expense of email ecosystem health and user trust. Prioritizing responsible sending is not just about avoiding blocklists (or blacklists), it's about building a credible and respected online presence.
Gmail and 
Outlook. Their algorithms are designed to protect users from unwanted mail, and cold emails often exhibit patterns consistent with spam. This makes it a constant uphill battle to achieve good inbox placement, especially with the latest email provider updates.
