Email Deliverability
Authentication, reputation, and list hygiene decide whether your email reaches the inbox or the spam folder. This guide covers DNS authentication, warming a new domain, and handling bounces and complaints.
🔐 SPF, DKIM & DMARC
Authenticate your sending domain before any volume. Without these, mailbox providers distrust you.
| Record | Purpose | Example |
|---|---|---|
| SPF | Authorizes sending servers | v=spf1 include:spf.afriroute.ai ~all |
| DKIM | Cryptographically signs mail | CNAME provided on domain setup |
| DMARC | Policy + reporting | v=DMARC1; p=quarantine; rua=mailto:[email protected] |
Verify setup via the API:
curl https://api.afriroute.ai/api/v1/email/domains/example.com \
-H "Authorization: Bearer $AFRIROUTE_API_KEY"
{ "domain": "example.com", "spf": "verified", "dkim": "verified", "dmarc": "pending" }
🔥 Domain Warm-up
A brand-new domain has no reputation. Ramp volume gradually so providers learn to trust you.
| Day range | Daily volume |
|---|---|
| 1–3 | 50–200 |
| 4–7 | 500–1,000 |
| 8–14 | 2,000–10,000 |
| 15+ | Scale to target |
Send to your most engaged recipients first — opens and replies build reputation fastest.
📉 Bounce & Complaint Handling
Listen for engagement events on your webhook and act on them automatically.
app.post('/webhooks/email', (req, res) => {
const { type, email } = req.body;
if (type === 'hard_bounce' || type === 'complaint') suppress(email);
res.sendStatus(200);
});
def handle_event(event):
if event['type'] in ('hard_bounce', 'complaint', 'unsubscribe'):
suppression_list.add(event['email'])
- Hard bounce → suppress immediately (address invalid).
- Soft bounce → retry a few times, then suppress.
- Complaint → suppress and review the content/segment.
Keep bounce rate under ~2% and complaint rate under ~0.1% to protect reputation.
💡 Best Practices
- Verify SPF, DKIM, and DMARC before sending anything.
- Warm up new domains over 2+ weeks.
- Suppress bounces and complaints automatically.
- Use a dedicated subdomain (e.g.
mail.example.com) for sending. - Authenticate links and avoid raw URL shorteners.
- Monitor reputation and engagement trends, not just delivery.
⚠️ Common Pitfalls
- Sending full volume from a cold domain — instant spam folder.
- Buying or mailing stale lists — high bounces tank reputation.
- Ignoring DMARC reports that reveal spoofing or misconfiguration.
📚 Related Resources
Last Updated: May 2026