Does SPF, DKIM, and DMARC stop emails going to spam?

They are necessary but not sufficient. Correct authentication is one of the strongest signals to inbox providers, but reputation, reverse DNS, blocklist status, and engagement also matter. Fix authentication first, then address the rest.

How do I check if my domain is blocklisted?

Check your sending domain and IP against the major DNS-based blocklists. Continuous blocklist monitoring will alert you when a domain becomes listed so you can request delisting before deliverability suffers.

Home
/
Help
/
Why Is My Email Going to Spam?

Why Is My Email Going to Spam?

Q: Why is my email going to spam?

The most common causes are missing or misconfigured email authentication (SPF, DKIM, DMARC), missing reverse DNS on the sending server, the sending domain or IP being on a blocklist, poor sender reputation, and spammy content or formatting.

When legitimate email keeps landing in the spam folder, the cause is far more often DNS and authentication than the words in your message. Work through this checklist roughly in order — the first few items resolve the majority of deliverability problems.

1. Fix email authentication first

This is the single biggest factor. Make sure all three records are present and correct: SPF, DKIM, and DMARC. A failing or misaligned check is a strong spam signal. See SPF vs DKIM vs DMARC if you are unsure which you are missing.

2. Check reverse DNS (PTR)

Many inbox providers reject or downgrade mail from an IP with no reverse DNS (PTR) record, or one that does not match the sending host name. If you run your own mail server, confirm its IP has a matching PTR record. (Hosted email providers handle this for you.)

3. Check blocklists

If your domain or sending IP has landed on a DNS-based blocklist, deliverability drops sharply. Check the major lists, request delisting where warranted, and find the root cause (often a compromised account or a misconfigured form). ZoneWatcher's blocklist monitoring alerts you the moment a domain is listed.

4. Sender reputation and engagement

Inbox providers track how recipients treat your mail. Low open rates, spam-button complaints, and sending to stale or purchased lists all erode reputation. Send to people who expect to hear from you, make unsubscribing easy, and remove addresses that bounce.

5. Content and formatting

Avoid spam-trigger phrasing, all-caps subjects, and excessive exclamation marks.
Keep a reasonable text-to-image ratio; an image-only email is a red flag.
Make sure every link points to a reputable domain, and avoid URL shorteners.
Include a working unsubscribe link and a valid physical address where required.

6. Sending infrastructure

A brand-new IP or domain has no reputation and needs warming up — ramp volume gradually rather than blasting on day one. For meaningful volume, a dedicated IP gives you control over your own reputation instead of sharing the fate of other senders on a shared pool.

Quick checklist

SPF, DKIM, and DMARC all present, passing, and aligned.
Reverse DNS (PTR) set and matching your sending host.
Domain and IP clear of blocklists.
Healthy engagement and a clean recipient list.
No spammy content, broken links, or missing unsubscribe.
Warmed-up, reputable sending IP.