How to improve email deliverability for a CEO's cold outreach and protect domain reputation?
Michael Ko
Co-founder & CEO, Suped
Published 22 Apr 2025
Updated 18 Aug 2025
7 min read
When a CEO engages in cold outreach, especially by sending emails manually via Gmail to a large group using BCC, it often leads to significant email deliverability challenges and a damaged domain reputation. This approach typically results in low reply rates and emails landing in spam folders, impacting legitimate communications from the primary domain. The problem stems from practices that, while seemingly convenient, violate modern email sending standards.
Even if the recipients are known contacts, sending unsolicited bulk emails without explicit consent for regular updates can be flagged by email service providers (ESPs). This lack of proper permission and the use of BCC, which obscures recipient lists, are critical factors that harm sender reputation and cause messages to be filtered into spam. Addressing these issues requires a strategic shift in how outreach is conducted, prioritizing transparency, consent, and technical email hygiene.
Understanding the problem
The fundamental issue with sending cold outreach, even to known contacts, without their explicit consent for regular updates is that it is often still classified as unsolicited communication by email service providers. When emails are sent in bulk via BCC, it's a red flag for spam filters because it's a common tactic used by spammers to hide recipient lists. This practice lacks transparency and prevents recipients from seeing who else received the email, further contributing to a negative sender score.
Domain reputation is a critical factor in email deliverability. Every time an email is sent, the sending domain is evaluated by recipient mail servers based on various metrics, including spam complaints, bounce rates, and engagement. When a high volume of unsolicited emails are sent from the primary domain, it can quickly erode its reputation, leading to legitimate business communications also being sent to spam. This is why practices like those described become so detrimental.
Monitoring your email reputation and deliverability is essential for understanding your current standing. Without visibility into inbox placement, bounce rates, and spam complaints, it’s impossible to diagnose the problem effectively. Using a standard email client for bulk sending, like Gmail's manual BCC feature, offers no such insights, leaving you blind to how your emails are performing.
A damaged reputation can take time to recover. Once a domain is listed on a blocklist (or blacklist), it can severely affect email deliverability across all recipients. You can learn more about what happens when your domain is on an email blacklist here. It’s a costly lesson to learn, often requiring significant effort to rebuild trust with ESPs.
Stopping the damage and building a foundation
To stop harming your primary domain reputation, the immediate step is to cease the current bulk BCC sending practice. This is non-negotiable for long-term email health. The next critical step is to implement proper email authentication, including SPF, DKIM, and DMARC. These protocols verify that your emails are legitimately from your domain and haven't been tampered with, significantly boosting your sender credibility with ESPs.
Current risky approach
Manual BCC sending: No visibility into bounces, spam complaints, or opens.
Using primary domain: Puts the core business domain at risk for blacklisting.
Lack of consent: Sending unsolicited bulk emails is a major deliverability pitfall.
Professional outreach platform: Provides tracking, personalization, and compliance features.
Consent-based sending: Prioritize sending to genuinely engaged recipients.
A simple guide to DMARC, SPF, and DKIM explains these authentication methods in detail. For CEOs, ensuring their domain has these records correctly configured is fundamental. This technical setup forms the bedrock of good email deliverability.
Leveraging subdomains and smart sending
One of the most effective strategies to protect your main domain is to use a dedicated subdomain for cold outreach, such as outreach.yourdomain.com. This isolates any potential deliverability issues, like blacklistings (or blocklistings), to the subdomain, keeping your primary domain's reputation intact for transactional and marketing emails. This allows for more aggressive outreach tactics without jeopardizing the core business communications. You can learn how to prevent cold emails from harming your domain reputation.
Once you have a dedicated subdomain, it's crucial to warm it up properly. Domain warm-up involves gradually increasing your sending volume over time, mimicking natural email activity. This helps ESPs recognize your subdomain as a legitimate sender. Neglecting to warm up a new subdomain will likely lead to emails going to spam right away. You can find more information on this topic in our article, How to improve email deliverability with domain warm-up.
List segmentation and cleaning are equally important. Instead of sending to a broad list, segment it based on prior engagement. Focus on those who have previously opened or clicked your emails. Regularly clean your lists to remove invalid or unengaged addresses. Sending to unengaged recipients or email addresses that result in bounces can severely damage your domain reputation. EmailToolTester.com emphasizes monitoring email list health as a key deliverability best practice.
Finally, consider the content of your emails. Avoid spammy keywords, excessive links, or overly promotional language. Personalize emails as much as possible to increase engagement and reduce the likelihood of them being marked as spam. A natural, conversational tone generally performs better than highly formatted, sales-driven messages in cold outreach.
Monitoring and recovery
To gain visibility into inbox placement and bounce rates, you need to move away from manual Gmail BCC sending. Transitioning to a professional email outreach platform is essential. These platforms offer detailed analytics that allow you to track key metrics, identify issues, and adapt your strategy. While I cannot recommend specific tools, platforms designed for sales outreach often include features for managing sender reputation and provide crucial insights.
Continuous monitoring of your Google Postmaster Tools domain reputation is vital. This provides data on spam rates, IP reputation, domain reputation, and DMARC failures, helping you pinpoint problems early. Regular checks allow you to see how ESPs view your sending practices and respond quickly to any negative trends. Mastering email sender and domain reputation is key for sustained deliverability.
If your domain or IP address ends up on a blacklist, immediate action is required. This often involves requesting delisting and demonstrating improved sending practices. Tools that provide blocklist monitoring can alert you quickly if your domain is listed, allowing for prompt intervention. This proactive approach is crucial for maintaining a healthy sending reputation and ensuring your important communications reach their intended recipients.
Views from the trenches
Best practices
Always seek explicit consent before adding anyone to a bulk email list, even if they are known contacts or investors.
Utilize a dedicated subdomain for any cold outreach or mass communications to isolate reputation risks from your primary domain.
Implement and monitor email authentication protocols like SPF, DKIM, and DMARC to build and maintain trust with mail servers.
Warm up new sending domains or subdomains gradually, increasing volume over time to establish a positive sending history.
Regularly clean your email lists to remove inactive, invalid, or unengaged addresses to reduce bounces and spam complaints.
Common pitfalls
Using BCC for bulk emails, as it lacks transparency and is a common indicator of spamming behavior for email service providers.
Sending high volumes of unsolicited emails from your primary domain, which can quickly damage its reputation for legitimate communications.
Ignoring bounce rates and spam complaint metrics, leading to a lack of awareness about deliverability issues until they become severe.
Failing to implement proper email authentication, which makes your emails look suspicious and more likely to be filtered.
Believing that simply knowing a contact bypasses the need for explicit consent for ongoing, non-personal bulk communications.
Expert tips
If immediate cold outreach is necessary, first send an invitation for recipients to opt-in to regular updates to formalize consent.
Transition from manual BCC sending to an email outreach platform that offers detailed analytics and controlled sending features.
Consult with a deliverability expert for a forensic audit of your email program if you're experiencing persistent deliverability issues.
Educate leadership on the long-term consequences of aggressive, non-compliant email sending practices on domain reputation and business operations.
Personalize emails deeply and focus on valuable content to encourage engagement, which is a strong positive signal for ESPs.
Expert view
Expert from Email Geeks says to immediately stop sending cold emails, as this practice is detrimental to domain reputation.
2025-06-10 - Email Geeks
Expert view
Expert from Email Geeks says that the first step is to cease spamming before any reputation repair can begin.
2025-06-10 - Email Geeks
Navigating cold outreach successfully
Improving email deliverability for a CEO’s cold outreach and protecting domain reputation requires a shift from risky, unmonitored practices to a strategic, compliant approach. This involves a commitment to ethical sending, proper technical setup, and continuous monitoring.
By stopping problematic BCC sending, implementing robust authentication, utilizing dedicated subdomains for outreach, and engaging with recipients who have opted in, you can significantly improve your deliverability. This proactive stance not only ensures your important messages reach the inbox but also safeguards your brand's invaluable online reputation for the long term.
