Glossary · CRM & retentionTOFU
Deliverability
The short answer
Deliverability is the ability of your emails to reach recipients' inboxes rather than spam folders or nowhere at all. It's distinct from delivery rate: an email can be "delivered" to the spam folder.
What decides deliverability
- Authentication — SPF, DKIM and DMARC set up correctly
- Sender reputation — built from engagement and complaint history
- List quality — valid, opted-in, engaged recipients
- Content — relevant, not spammy
- Sending patterns — consistent volumes, gradual warm-up
Protecting it
- Authenticate your sending domain
- Include easy one-click unsubscribe
- Remove bounces and long-term non-engagers
- Keep spam complaints very low
- Warm up new domains and IPs gradually
In practice
Brands often damage deliverability during sale periods by suddenly emailing their entire historical list, including people who haven't opened anything in a year. Segment by engagement and ramp up volume in the weeks before a big sale instead.
Deliverability checklist
- SPF, DKIM and DMARC records configured
- Dedicated sending subdomain
- One-click unsubscribe
- Complaint rate kept very low
- Inactive subscribers suppressed
- No purchased lists
- Gradual warm-up for new domains
See email marketing.
Deliverability in practice
A brand's emails start landing in spam after sending to old, unengaged lists. Authenticating the domain, removing inactive subscribers and sending to engaged segments restores inbox placement.
Deliverability essentials
- SPF, DKIM and DMARC authentication
- Clean, consented lists
- Consistent sending volume
- Easy unsubscribe
Deliverability in India
Indian brands often build large lists through contests and promotions, which can hurt deliverability later. Clean, consented lists and engagement-based sending protect inbox placement.
Frequently asked questions
Why did our emails suddenly go to spam?
Common causes include a spike in complaints, sending to old or purchased lists, broken authentication or sudden volume increases.
How do I check if my emails land in spam?
Use seed-list testing tools, monitor provider dashboards such as Google Postmaster Tools, and watch for sudden drops in clicks from specific mailbox providers.
What is a spam complaint rate?
The share of recipients marking your email as spam. Google advises keeping it well below 0.3%.
Does sending volume affect deliverability?
Sudden spikes, especially from new domains, can trigger filtering. Increase volume gradually.
Why do emails go to spam?
Poor sender reputation, missing authentication, spam complaints and low engagement are common causes.
How do we check deliverability?
Monitor bounce rates, spam complaints, engagement and inbox-placement tests.
Related terms
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