Email deliverability checklist: beyond SPF, DKIM and DMARC
SPF, DKIM and DMARC are the entry ticket, not the destination. Plenty of domains with all three configured correctly still land in spam because of what comes next.
1. Check DMARC alignment, not just presence
DMARC passes when the domain in the From header aligns with the domain SPF or DKIM validated. Using a third-party sender's domain in your Return-Path breaks alignment even if SPF passes.
Relaxed alignment allows subdomain matches; strict requires an exact match.
Prefer sending through your own (sub)domain so alignment is native.
Verify with a DMARC report or our free checker.
2. Get reverse DNS right
Your sending IP should have a PTR record that resolves back to a hostname your domain owns. Many receivers treat a mismatched or missing PTR as a spam signal.
3. Watch your sending reputation
Shared IPs inherit the reputation of everyone on them. If you send high volume or transactional mail, a dedicated IP you warm up gradually keeps you in control.
4. Practise list hygiene
Never buy lists.
Use double opt-in for newsletters.
Remove hard bounces immediately and prune the long-term unengaged.
Make unsubscribing one click, and honour it fast.
5. Warm up new IPs gradually
Sending your full volume from a brand-new IP looks like spam. Ramp up over a few weeks, starting with your most engaged recipients.
6. Read your DMARC reports
Set a rua address and actually read the XML (or use a free aggregator). Reports show you who is sending as your domain — legitimate senders you forgot to authorise, and spoofers you can move to p=quarantine or p=reject.
7. Test the whole path
Send to Gmail, Outlook and a smaller provider, then read the Authentication-Results header to confirm SPF, DKIM and DMARC all pass. Fix alignment issues before blaming the content.
Work through this list in order and you will move from 'sometimes lands' to 'reliably lands'. Our business email plans include the DNS records and guidance to get it right from day one.