Email deliverability
In short
Email deliverability is the ability of your emails to reach the inbox of the intended recipient. It is influenced by sender reputation, technical authentication, list quality, and how recipients react to your messages.
Delivered and deliverable are not the same. An email can be accepted by a server yet land in spam, so inbox placement is the real measure of deliverability.
Deliverability vs. delivery
Delivery means the receiving server accepted the message. Deliverability means it reached the inbox. A campaign can show 99% delivered and still have most messages in spam.
What affects deliverability
- Authentication: SPF, DKIM, and DMARC prove you are allowed to send for your domain.
- Sender reputation: Built from bounces, complaints, and engagement over time.
- List quality: Verified, relevant recipients protect your reputation.
- Content and formatting: Spammy wording, heavy images, and many links can trigger filters.
- Sending patterns: Sudden volume spikes look suspicious.
- Engagement: Replies help; ignored mail and spam reports hurt.
How to improve it
Fix the technical basics
Set up SPF, DKIM, and DMARC, and use a consistent sending domain.
Clean your lists
Verify addresses and remove hard bounces and non-responders to keep bounce rate low.
Warm up and ramp slowly
New domains need gradual volume increases before full campaigns.
Write for people
Plain, relevant, short messages with an easy way to opt out perform better than promotional formatting.
Monitor
Check inbox placement with seed tests, and watch bounce and spam complaint rates for each campaign.
Common mistakes
- Judging by delivered rate alone: Spam placement is invisible there.
- Using the primary domain for risky volume: Damage there can affect all company email.
- Ignoring complaints: Even small complaint rates can hurt reputation.
- Buying unverified lists: High bounces and complaints follow.
Email deliverability FAQs
What is email deliverability?
Email deliverability is the ability of your emails to land in the recipient’s inbox rather than the spam folder or being rejected. It depends on sender reputation, authentication, list quality, content, and recipient engagement.
What is the difference between email delivery and email deliverability?
Delivery means the receiving server accepted your message. Deliverability means the message actually reached the inbox. Mail can be delivered to a server and still be filtered into spam, so inbox placement is the better measure.
How do you improve email deliverability for cold outreach?
Authenticate your domain with SPF, DKIM, and DMARC, verify lists, warm up new domains, keep volume steady, write relevant plain-text messages, and monitor bounce and spam complaint rates. Pause campaigns when metrics worsen.
Why are my emails going to spam?
Common causes include missing authentication, poor sender reputation, high bounce or complaint rates, sudden volume spikes, spammy wording, and low engagement. Check authentication first, then list quality and recent sending patterns.
