Email Deliverability Guide
Reaching the inbox is only half the battle. Learn how to build and maintain strong sender reputation so your emails land where they belong — in the inbox, not spam.
Email deliverability refers to the ability of your emails to reach subscribers' inboxes. Major factors include domain authentication, sender reputation, email content, and list quality. Neglecting any one of these can result in emails being routed to spam or blocked entirely.
Healthy benchmarks
Aim to stay within these ranges for your industry:
Open rate
> 20%
Click rate
> 2%
Bounce rate
< 2%
Spam complaint rate
< 0.1%
Unsubscribe rate
< 0.5%
1Authenticate your domain
- Set up SPF, DKIM, and DMARC records (see our DNS Setup Guide).
- Use a custom domain — never send campaigns from @gmail.com or @yahoo.com.
- Start with DMARC policy p=none, then graduate to p=quarantine as you gain confidence.
2Warm up your sending IP
- Start with small volumes (50–100/day) and increase by 30–50% every 3–5 days.
- Send to your most engaged contacts first — high open rates signal good sender reputation.
- Avoid sending large one-off blasts. Consistent daily volume is better than spikes.
3Maintain list hygiene
- Remove hard bounces immediately and soft bounces after 3–5 attempts.
- Remove contacts who haven't engaged in 90+ days or run a re-engagement campaign first.
- Never purchase email lists — they contain spam traps and dramatically hurt deliverability.
- Use double opt-in for new subscribers.
4Write better email content
- Avoid spam trigger words like 'FREE!!!', 'Act now', 'Guaranteed', 'No risk'.
- Maintain a healthy text-to-image ratio (more text than images).
- Always include a plain-text version of your email.
- Use a clear, recognisable sender name and reply-to address.
5Monitor your metrics
- Keep open rate above 20% and click rate above 2% — lower rates signal disengagement.
- Keep bounce rate below 2% and spam complaint rate below 0.1%.
- Monitor your domain's reputation with Google Postmaster Tools and Senderscore.org.
- Set up bounce and complaint webhook handlers to act on events in real time.
6Send at the right time
- Tuesday–Thursday, 9–11 am recipient local time consistently outperform other windows.
- Avoid major holidays and Fridays for B2B audiences.
- Test send times with A/B splits and let data guide your decisions.
Quick summary
Great deliverability comes down to three things: proving you are who you say you are (authentication), earning trust over time (sender reputation), and respecting your recipients (list hygiene and content quality). DevMail handles the technical infrastructure — the rest is up to you.