Email deliverability
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The percentage of sent emails that actually reach the recipient's inbox. The foundation of every email marketing program.
Deliverability is whether your emails reach the inbox or get caught by spam filters. If your deliverability is 95%, 5 out of every 100 emails you send never reach the recipient. They go to spam, get blocked by the server, or bounce.
Deliverability depends on three things. Sender reputation: have you sent spammy emails in the past? Content quality: does the email look like spam (excessive links, trigger words, misleading subject lines)? Technical setup: are your SPF, DKIM, and DMARC records configured correctly?
Poor deliverability silently kills email marketing. Your open rates drop. Your campaigns underperform. And you might not even know why because bounced and filtered emails do not generate visible errors. Monitor deliverability actively: track bounce rates, spam complaint rates, and inbox placement using tools like Postmark or SendGrid.
Examples
A deliverability problem goes undetected.
Open rates drop from 35% to 18% over three months. The team blames content quality. Investigation reveals that 25% of emails are landing in spam due to a misconfigured DKIM record. Fixing the DNS record restores open rates to 32% within two weeks.
A cold email campaign damages sender reputation.
The BDR team sends 5,000 cold emails in a week from the main company domain. Spam complaint rate spikes to 2%. Gmail starts routing all emails from the domain to spam, including marketing newsletters and customer communications. The company has to warm the domain back up over 6 weeks.
Maintaining healthy deliverability.
Best practices: authenticate with SPF, DKIM, and DMARC. Clean the email list quarterly (remove bounced and inactive addresses). Keep spam complaint rates below 0.1%. Use a separate domain for cold outreach. Monitor inbox placement weekly.
In practice
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Frequently asked questions
What is a good email deliverability rate?
Above 95% is healthy. Above 98% is excellent. Below 90% means you have a deliverability problem that needs immediate attention. Check your authentication records, clean your list, and review your sending patterns.
How do you improve email deliverability?
Set up SPF, DKIM, and DMARC authentication. Clean your list regularly (remove bounces and inactive subscribers). Keep spam complaint rates below 0.1%. Use consistent sending patterns. Avoid spam trigger words. Use a reputable email service provider.
Related terms
The percentage of delivered emails that recipients opened. A proxy for subject line effectiveness and sender trust.
The percentage of sent emails that were not delivered. Hard bounces are permanent failures. Soft bounces are temporary.
A score assigned to your email domain and IP address by email providers. Determines whether your emails reach the inbox or spam folder.
A recurring email to subscribers with curated content, insights, or updates. The most valuable owned audience channel in B2B marketing.
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