What is Email Deliverability?
Email deliverability is the ability to deliver emails to recipients’ inboxes. Poor deliverability means your emails end up in spam folders or get rejected entirely.95%+
Target inbox rate
<0.1%
Target spam complaint rate
<2%
Target bounce rate
Email Authentication
Authentication proves you’re authorized to send from your domain. Set up these DNS records:SPF (Sender Policy Framework)
SPF (Sender Policy Framework)
Specifies which mail servers can send email on behalf of your domain.
DKIM (DomainKeys Identified Mail)
DKIM (DomainKeys Identified Mail)
Adds a digital signature to verify email hasn’t been altered.✓ Automatically configured when you verify your domain
DMARC (Domain-based Message Authentication)
DMARC (Domain-based Message Authentication)
Tells receiving servers what to do with unauthenticated emails.
Sender Reputation
Your sender reputation is a score that email providers use to decide if your emails should be delivered. Here’s how to build and maintain a good reputation:- ✓ Start slow - Warm up new domains by gradually increasing send volume
- ✓ Send to engaged users first - High open rates early on boost your reputation
- ✓ Keep lists clean - Remove bounced emails and inactive subscribers
- ✓ Monitor complaints - Keep spam complaint rate below 0.1%
- ✓ Be consistent - Send regularly from the same domain
Content Best Practices
Subject Lines
DO ✓
- Be clear and specific
- Keep it under 50 characters
- Personalize when possible
- Create urgency naturally
DON'T ✗
- Use ALL CAPS
- Add excessive punctuation!!!
- Use spam trigger words (FREE!!!)
- Mislead about content
Email Body
DO ✓
- Include plain text version
- Use a good text-to-image ratio
- Include unsubscribe link
- Add your physical address
- Make links clearly visible
DON'T ✗
- Use link shorteners
- Embed forms in emails
- Use image-only emails
- Hide unsubscribe links
- Include attachments (use links)
List Hygiene
Maintain a clean email list to protect your sender reputation:1
Remove Hard Bounces
Immediately remove emails that hard bounce. Continued sending damages reputation.
2
Re-engage or Remove Inactive
After 6 months of no opens, send a re-engagement campaign. Remove those who don’t respond.
3
Use Double Opt-in
Require email confirmation to ensure valid addresses and genuine interest.
4
Honor Unsubscribes
Process unsubscribe requests immediately. Never re-add without explicit consent.
Domain Warm-up
New domains need to build reputation gradually. Here’s a recommended warm-up schedule:| Week | Daily Volume | Notes |
|---|---|---|
| Week 1 | 50-100 | Most engaged subscribers only |
| Week 2 | 200-500 | Expand to recent subscribers |
| Week 3 | 1,000-2,000 | Include more of your list |
| Week 4 | 5,000-10,000 | Nearly full list |
| Week 5+ | Full volume | Monitor metrics closely |
Troubleshooting
Emails going to spam?
Emails going to spam?
- Check that SPF, DKIM, and DMARC are properly configured
- Review your subject lines for spam triggers
- Ensure you have a plain text version
- Add unsubscribe link and physical address
- Check your sender reputation at Google Postmaster Tools
High bounce rate?
High bounce rate?
- Clean your list - remove invalid addresses
- Use double opt-in for new subscribers
- Verify email addresses at sign-up
- Don’t buy email lists
Low open rates?
Low open rates?
- Improve subject lines - A/B test different approaches
- Send at optimal times for your audience
- Segment and personalize content
- Re-engage or remove inactive subscribers
Deliverability Checklist
- Domain verified with SPF, DKIM, and DMARC
- Unsubscribe link included in all emails
- Physical address included in emails
- Plain text version of all emails
- Bounce rate below 2%
- Spam complaint rate below 0.1%
- Regular list cleaning schedule
- Monitoring Google Postmaster Tools