Email Glossary

Email Deliverability

Email deliverability measures how successfully your emails reach the intended inbox rather than being blocked, bounced, or filtered to spam. It's influenced by sender reputation, authentication, content, and recipient engagement.

What Affects Deliverability

Deliverability depends on multiple factors:

Sender Reputation

  • ●IP reputation (shared vs dedicated)
  • ●Domain reputation
  • ●Historical sending patterns
  • ●Complaint rates

Authentication

  • ●SPF, DKIM, DMARC setup
  • ●Proper alignment

Content & Engagement

  • ●Spam trigger words
  • ●HTML quality
  • ●Open and click rates
  • ●Unsubscribe rates

List Quality

  • ●Bounce rates
  • ●Spam complaints
  • ●Invalid addresses

Measuring Deliverability

Key metrics to track:

Delivery Rate = Emails delivered / Emails sent Target: 95%+

Inbox Placement Rate = Emails in inbox / Emails delivered Target: 85%+

Bounce Rate = Bounced emails / Emails sent Hard bounces should be under 2%

Complaint Rate = Spam complaints / Emails delivered Keep under 0.1%

Use inbox placement tools to test where your emails actually land across major providers.

Common Deliverability Issues

Emails going to spam

  • ●Missing or misconfigured authentication
  • ●Poor sender reputation
  • ●Spammy content or subject lines
  • ●Sending to unengaged recipients

High bounce rates

  • ●Outdated or purchased lists
  • ●Typos in email collection
  • ●No email validation on signup

Getting blacklisted

  • ●Sudden volume spikes
  • ●High complaint rates
  • ●Sending to spam traps
  • ●Compromised account sending spam

Improving Deliverability

  • ●Set up authentication - SPF, DKIM, and DMARC are mandatory
  • ●Warm up new domains/IPs - Gradually increase volume over weeks
  • ●Clean your lists - Remove bounces, complaints, and inactive subscribers
  • ●Monitor engagement - Remove subscribers who never open
  • ●Make unsubscribing easy - Hidden unsubscribe links lead to complaints
  • ●Send consistently - Erratic patterns look suspicious
  • ●Use double opt-in - Confirms real, engaged subscribers

Related Tools

DNS Checker

Related Terms

SPF (Sender Policy Framework)

Tells receiving servers which IPs can send email for your domain.

DKIM (DomainKeys Identified Mail)

Adds a digital signature to emails proving they haven't been tampered with.

DMARC (Domain-based Message Authentication)

Tells email receivers how to handle messages that fail SPF or DKIM checks.

Email Warmup

Gradually increasing email volume to build sender reputation with ISPs.

Bounce Rate

The percentage of sent emails that couldn't be delivered to the recipient.

Sender Reputation

A score ISPs assign to your sending IP and domain based on email behavior.

Frequently Asked Questions

Why are my emails going to spam?
Common causes include missing SPF/DKIM/DMARC, poor sender reputation, spammy content, sending to old lists, or using shared IPs with bad neighbors. Check your authentication first, then review your sending practices and list hygiene.
How long does it take to fix deliverability?
It depends on the severity. Authentication fixes take effect within hours. Reputation recovery can take weeks to months. Warming up a new domain properly takes 4-8 weeks. Consistent, quality sending is the fastest path to improvement.
Does email content affect deliverability?
Yes, but less than authentication and reputation. Avoid spam trigger words, maintain a good text-to-image ratio, include a plain text version, and don't use link shorteners. However, a spammy reputation will hurt you more than any content.
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