Emails landing in spam usually comes down to a combination of authentication, reputation, and content factors rather than one single cause.
Checklist to diagnose it
- Confirm SPF, DKIM, and DMARC are all correctly configured and passing — check this first, it’s the most common root cause
- Check your sending IP/domain reputation against blacklists
- Review recent complaint rate — a spike suggests content or targeting issues, not technical misconfiguration
- Check content for spam-trigger patterns: excessive links, spammy phrases, poor image-to-text ratio
- Confirm you’re not sending to old, unengaged, or purchased lists, which drives up bounce and complaint rates
If it’s a new domain
New sending domains have no reputation yet; gradually ramping up volume over several weeks ("warm-up") rather than sending a large volume immediately is standard practice to build trust with mail providers.
FAQ
Can perfect technical setup still land in spam?
Yes — content and engagement signals matter independently of authentication; a technically perfect setup with spammy content or a cold list can still be filtered.