Why Are My Emails Going to Spam?
Your emails are going to spam because mailbox providers like Gmail, Outlook, and Yahoo don't trust the message enough to place it in the inbox. That distrust comes from one (or more) of six things: missing authentication (SPF, DKIM, DMARC), a poor sender reputation, spammy content, a dirty list with high bounce rates, a blacklisted domain or IP, or low engagement from your recipients.
The good news: every one of these causes is diagnosable and fixable. If you only do two things, set up email authentication and verify your list before you send — together they resolve the majority of deliverability problems. Below, we break down each of the six causes, how to spot it, and exactly how to fix it, then give you a diagnostic order to work through when you're not sure which one is hurting you.
Already know the cause is your content?
If your authentication and list are clean and you suspect the message itself, jump straight to the email spam checker guide and run your draft through the free spam checker. This post covers the full picture — the technical and reputation causes that a content check alone won't catch.
1. Missing or Broken Authentication (SPF, DKIM, DMARC)
The most common technical reason emails go to spam is failing authentication. SPF, DKIM, and DMARC are DNS records that prove you're allowed to send mail from your domain. Since Google and Yahoo's 2024 sender requirements, bulk senders without all three properly configured are routinely filtered to spam or rejected outright.
SPF (Sender Policy Framework)
A DNS record listing which servers are allowed to send email for your domain. If your sending service isn't in the SPF record, providers can't confirm the mail is legitimate. Fix: add every sending source (your ESP, CRM, transactional service) to a single SPF TXT record.
DKIM (DomainKeys Identified Mail)
A cryptographic signature added to every message, verifying it wasn't altered in transit and genuinely came from your domain. Fix: enable DKIM signing in your sending platform and publish the public key it gives you as a DNS record.
DMARC
Ties SPF and DKIM together and tells providers what to do when a message fails ("none," "quarantine," or "reject"). Bulk senders now need at least a p=none DMARC policy. Fix: publish a DMARC TXT record at _dmarc.yourdomain.com and monitor the reports.
How to check it in 30 seconds
Run your domain through Enrichley's free domain health checker. It validates your SPF, DKIM, DMARC, and MX records in one step and shows you exactly which records are missing or misconfigured — the fastest way to rule authentication in or out as the cause.
2. Poor Sender Reputation
Sender reputation is the trust score mailbox providers assign to your domain and IP address. Every send either builds or erodes it. A low reputation means even perfectly authenticated, well-written emails get filtered to spam — because the provider has learned not to trust your history.
What damages sender reputation
- High bounce rates from sending to invalid addresses
- Spam complaints when recipients hit "report spam"
- Spam-trap hits from old or purchased lists
- Sudden volume spikes on a cold or unwarmed domain
The fix: warm up and stay consistent
Reputation recovers with time and consistency, not overnight. Warm up new sending domains by starting with low volume and increasing gradually. Keep a steady sending cadence rather than large bursts. Most importantly, only send to a clean, verified list — the fastest way to wreck a new domain is a wave of hard bounces on its first big send.
3. Spammy Content & Trigger Words
The words, links, and formatting in your email can trip spam filters even when everything else is perfect. Filters score every message, and certain patterns — aggressive sales language, ALL CAPS, excessive punctuation, or a wall of images with almost no text — push that score into spam territory.
Common triggers
- "Free," "guarantee," "act now," "100% free"
- ALL CAPS subject lines and !!! punctuation
- Image-heavy emails with little real text
- Link shorteners and mismatched link domains
- Misleading subject lines vs. body content
What to do instead
- Write like a person, not a billboard
- Keep a healthy text-to-image ratio
- Use your real domain in links
- Match the subject line to the content
- Always include a plain-text version
Test before you send
Run your draft through Enrichley's free spam checker to get a spam score and flag trigger words before you hit send. For the full list of words to avoid, see our guide to spam trigger words and the deeper dive on what a spam score is.
4. Bad List Hygiene & High Bounce Rates
A dirty list is the single most common fixable cause of spam placement. Every invalid address you send to produces a hard bounce, and a high bounce rate signals to mailbox providers that you don't maintain your list — a classic spammer behavior. Old lists also hide spam traps: addresses providers use specifically to catch senders who don't clean their data.
Keep bounce rates under 2%
Mailbox providers watch your bounce and complaint rates closely. The practical target is to keep bounce rates under about 2%. The way to get there is to verify your list before every major send:
- Remove invalid, malformed, and undeliverable addresses
- Flag disposable addresses and known spam traps
- Resolve catch-all domains instead of guessing
Not sure whether a bounce is permanent or temporary? Our guide on hard bounce vs. soft bounce explains which ones to remove immediately. And to understand how verification catches these addresses before they hurt you, see what email verification is.
Verify catch-all addresses others skip
Most verifiers mark catch-all (accept-all) domains as "risky" and leave you guessing. Enrichley verifies catch-all addresses individually in real time with 98% accuracy, so you can keep valid contacts on catch-all domains instead of blanket-removing them — and still protect your bounce rate.
5. Your Domain or IP Is Blacklisted
If your sending domain or IP is on a blacklist, your deliverability can collapse overnight. DNS blacklists (DNSBLs) like Spamhaus, Barracuda, and SpamCop track senders associated with spam. Many mailbox providers query these lists in real time, so a single listing can push most of your mail to spam — or block it entirely.
How to check and get delisted
Check your domain and IP
Run Enrichley's free blacklist checker to test your domain against major blacklists in one step.
Fix the root cause first
Clean your list, stop the source of complaints, and secure any compromised account. Delisting won't stick if the behavior that caused the listing continues.
Request delisting
Each blacklist has its own removal process. Submit a delisting request once the underlying issue is resolved, then monitor to confirm you stay off.
For a deeper walkthrough, read our full guide on how to know if your domain is blacklisted.
6. Low Engagement Signals
Mailbox providers watch how recipients interact with your mail. If people rarely open, never reply, and frequently delete without reading — or worse, mark you as spam — providers learn your mail isn't wanted and start routing it to the spam folder automatically, even for engaged subscribers.
How to raise engagement
- Send to people who actually opted in — permission drives engagement
- Segment and personalize so content is relevant to each group
- Prune inactive subscribers who haven't opened in months
- Make unsubscribing easy — an unsubscribe beats a spam complaint every time
Sending fewer, better emails wins
It's counterintuitive, but reducing volume to your most engaged recipients often improves inbox placement for everyone. A smaller, engaged list beats a large, indifferent one on every deliverability metric.
How to Diagnose It (in Order)
Not sure which of the six is hurting you? Work through them in this order — it goes from the fastest, highest-impact checks to the slower reputation work.
Check authentication
Run the domain health checker to confirm SPF, DKIM, DMARC, and MX all pass. This is the #1 cause and takes seconds.
Check for a blacklist listing
Run the blacklist checker. A listing explains a sudden, dramatic drop.
Verify your list
Clean out invalid addresses and get your bounce rate under about 2% before the next send.
Score your content
Run the draft through the spam checker to catch trigger words and formatting problems.
Rebuild reputation and engagement
Once the technical causes are ruled out, send consistently to a verified, engaged list and let reputation recover over two to four weeks. For a full pre-send routine, see the email deliverability test guide.
Frequently Asked Questions
Why are my emails going to spam all of a sudden?
How do I stop my emails from going to spam?
Does SPF, DKIM, and DMARC really affect spam placement?
Can a bad email list send my emails to spam?
How do I know if my domain is blacklisted?
How long does it take to fix deliverability?
Diagnose Your Deliverability in Minutes
Check your SPF, DKIM, DMARC, and MX records with the free domain health checker, then score your message with the spam checker — the two fastest ways to find out why your emails are going to spam.