Email Deliverability
Best practices to ensure your emails reach the inbox and avoid spam folders. Learn about authentication, content optimization, and sender reputation.
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.
Email Authentication
Authentication proves you're authorized to send from your domain. Set up these DNS records:
SPF (Sender Policy Framework)
Specifies which mail servers can send email on behalf of your domain.
v=spf1 include:spf.unosend.co ~allDKIM (DomainKeys Identified Mail)
Adds a digital signature to verify email hasn't been altered.
DMARC (Domain-based Message Authentication)
Tells receiving servers what to do with unauthenticated emails.
v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.comSender 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:
Warm up new domains by gradually increasing send volume
High open rates early on boost your reputation
Remove bounced emails and inactive subscribers
Keep spam complaint rate below 0.1%
Send regularly from the same domain
Content Best Practices
Subject Lines
- • Be clear and specific
- • Keep it under 50 characters
- • Personalize when possible
- • Create urgency naturally
- • Use ALL CAPS
- • Add excessive punctuation!!!
- • Use spam trigger words (FREE!!!)
- • Mislead about content
Email Body
- • Include plain text version
- • Use a good text-to-image ratio
- • Include unsubscribe link
- • Add your physical address
- • Make links clearly visible
- • 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:
Remove Hard Bounces
Immediately remove emails that hard bounce. Continued sending damages reputation.
Re-engage or Remove Inactive
After 6 months of no opens, send a re-engagement campaign. Remove those who don't respond.
Use Double Opt-in
Require email confirmation to ensure valid addresses and genuine interest.
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?
- • 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?
- • 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?
- • 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