If you’re sending emails that never reach the inbox, you’re not just wasting time — you’re missing opportunities. Every email that lands in a spam folder, bounces back, or simply disappears represents lost chances to connect with prospects, nurture leads, and drive revenue.
Whether you’re a salesperson trying to land meetings or a marketer aiming to engage your audience, poor deliverability can hurt your outreach efforts. Most deliverability issues are preventable with the right setup, preparation, and ongoing care.
In this post, we’ll explore the most common reasons emails fail to get delivered and the practical steps you can take to increase your chances of reaching the inbox.
This post is based on our recent webinar “Message Received: How to Optimize Your Email Deliverability.” We discussed real-life examples and actionable advice to improve email success. If you want to learn more, make sure to listen to the full webinar here.
Key Takeaways
- Deliverability starts long before you send your first email.
- Proper domain setup and authentication (SPF, DKIM, DMARC) are essential.
- Warming up your domain gradually helps avoid spam filters.
- A clean, validated, and segmented list protects your sender reputation.
- Personalization, content variety, and engagement signals improve inbox placement.
- New rules from providers like Google and Microsoft require unsubscribe options.
Common Causes of Email Deliverability Issues (And How to Fix Them)
No Authentication Set Up
SPF, DKIM, and DMARC records form the core of your email’s identity. Without them, email providers cannot verify that you’re a legitimate sender. SPF tells the recipient which IP addresses are authorized to send emails on your behalf. DKIM adds a digital signature to verify the email wasn’t altered after being sent. DMARC connects these records and instructs providers on what to do if authentication fails. Without these records, your emails are likely to be flagged as spam or blocked.
What to Do: Work with your IT team or email service provider to set up your DNS records correctly. Many providers offer detailed guides. Do not guess your way through this. An incorrect setup can be just as damaging as having no authentication. Use tools to validate your SPF, DKIM, and DMARC records and ensure they are correctly configured.
Sending From a Poor Domain
The domain you use affects your deliverability. New domains or domains previously associated with spam often carry a weak reputation. Domains with unusual extensions, random numbers, or hyphens are commonly used by spammers. Even if your intentions are legitimate, providers may treat such domains with caution.
What to Do: Choose trusted top-level domains like .com or standard country-specific options. Avoid domains with odd characters or unfamiliar extensions. Whenever possible, purchase your domain from reputable providers like Google or Microsoft to start with a stronger reputation.
High Volume Too Soon
Email providers monitor sending patterns for signs of spam-like behavior. One warning sign is a sudden increase in email volume. If you immediately start sending hundreds or thousands of emails from a new domain, providers may view this as suspicious. Gradual increases signal that your sending behavior is normal.
What to Do: Start with 20 to 50 emails per day and slowly increase your volume over several weeks. Spread your emails throughout the workday rather than sending large batches all at once. Use scheduling tools to maintain consistent sending patterns. Consistency helps build trust with email providers.
Bad Email Lists
Your email list quality directly impacts your sender reputation. Purchased or scraped lists often contain invalid addresses, spam traps, and disengaged recipients. High bounce rates and low engagement send negative signals to email providers, which can lead to poor inbox placement or domain blocks.
What to Do: Use reputable list validation tools to regularly check your email lists. Remove invalid addresses, inactive users, and spam traps. Ensure your lists include accurate information like first names and job titles for personalization. Avoid buying lists from third-party vendors unless you can verify that the data is accurate and permission-based.
Spammy Content or Structure
Even with a perfect technical setup and a clean list, poor content can trigger spam filters. Using trigger words like “free,” “prize,” or “winner” raises suspicion. Too many links or attachments increase the risk. Generic addresses like sales@ or marketing@ can also signal automated or bulk messaging. Personalization errors, such as missing name fields, damage credibility.
What to Do: Personalized emails are more engaging and improve deliverability. Use recipient details to create varied content. Providers prefer individualized emails over identical mass messages. Spin tax tools can introduce variation while keeping messaging consistent. Keep links minimal and avoid sending heavy attachments. Always include a clear unsubscribe link to meet regulations and reduce spam complaints.
Conclusion
Email deliverability is often overlooked, yet it directly influences the success of your sales and marketing campaigns. With stricter regulations and smarter spam filters, writing a great email isn’t enough. You must ensure your email actually reaches the inbox.
Every part of the process matters, from domain selection and authentication to list hygiene and email content. The most successful email programs combine careful technical setup, ongoing monitoring, and respect for the recipient’s experience. Taking time to improve deliverability now will save frustration later and help you connect with the right audience more effectively.
