Are your website emails ending up in spam?
This is one of the most difficult issues to troubleshoot. The main reason is that the emails are actually being sent. Just not to the recipients’ inboxes.
In this guide, I’ll show you 5 checks that decide inbox placement. You’ll also learn how to confirm you’re really in spam, why transactional email fails differently, and how long recovery takes.
Let’s get started.
- Why Are My Emails Going to Spam?
- How to Confirm Emails Are Actually Going to Spam
- How Do Spam Filters Decide What to Block?
- What Should I Check First When Emails End Up in Spam?
- Why Transactional Emails Go to Spam
- What if Everything Passes and Mail Still Goes to Spam?
- How Long Does It Take to Get Out of the Spam Folder?
- Frequently Asked Questions
Why Are My Emails Going to Spam?
Your emails go to spam for one of 3 reasons. A mailbox provider can’t verify who you are, doesn’t trust your sending history, or sees that recipients don’t want your mail.
Every specific cause fits into one of 4 groups. Finding your group first saves you from having to work through a list of 19 fixes.
| Group | What the provider is asking | Common symptom | Where you fix it |
|---|---|---|---|
| Identity | Can I prove this mail is from you? | All mail to one provider fails at once | DNS records |
| Reputation | Has your mail caused problems before? | Placement gets worse over weeks | Sending habits |
| Permission | Do these people want your mail? | Some recipients fine, others not | Your list |
| Content | Does this message look like spam? | One campaign fails, others don’t | The email itself |
The pattern of failure tells you about the group. Mail failing at one provider only points to identity. Mail slowly getting worse everywhere points to a reputation issue.
Note: One message in one person’s junk folder isn’t a deliverability problem. Look for a pattern across recipients or providers before you change anything.
How to Confirm Emails Are Actually Going to Spam
Check a mailbox you don’t control, then confirm the pattern in Google Postmaster Tools. Sending a test to your own inbox proves nothing. Your own address already trusts you.
Do these 3 things before changing any settings:
- Send to fresh Gmail, Outlook, and Yahoo accounts that have never received your mail
- Open Postmaster Tools and check spam rate and authentication for your domain
- Read the headers on a message that landed in spam
How to Check Google Postmaster Tools
Add your sending domain to Postmaster Tools, then read the Spam rate and Authentication reports. Both are free. Both show what Gmail recorded, not what your app logged.
Go to postmaster.google.com » Spam rate and check the last 30 days. Treat any day above 0.3% as the first thing to fix.
Our guide on how to use Google Postmaster Tools covers setup and how to read each report.
Note: Postmaster Tools needs volume before it shows data. Low-volume senders often see empty reports. Use seed accounts and headers instead.
How to Read Email Headers to See What Failed
Open the message that went to spam and view its source. The Authentication-Results header tells you whether SPF, DKIM, and DMARC passed.
In Gmail, open the message, click the 3-dot menu, then click Show original.
Here’s a header from a message that failed DKIM:
Authentication-Results: mx.google.com;
dkim=fail [email protected] header.s=default;
spf=pass (google.com: domain of [email protected] designates
198.51.100.24 as permitted sender) [email protected];
dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=example.com
Read it from the bottom up. DMARC failed here because DKIM failed, even though SPF passed. So the fix is the DKIM record, not the SPF one.
Pro Tip: Save one passing header and one failing header. Comparing the two takes 30 seconds and beats guessing at your DNS.
How Do Spam Filters Decide What to Block?
Spam filters score every message on 3 inputs: who sent it, how that sender has behaved, and how recipients respond. The score is then compared against a threshold that shifts per recipient.
Recipient behavior carries the most weight. Providers watch opens, replies, deletes without reading, and complaints. Those signals act as a verdict on whether people want your mail.
That’s why 2 identical messages can land differently. The filter isn’t only reading your email. It’s reading your history with each person.
Only one of these numbers is published. Google’s sender guidelines set the spam rate limit at 0.3%. They recommend staying under 0.10% and never reaching 0.30%. That’s 3 complaints in a thousand messages, not 3 in a hundred.
Everything else is inferred from behavior. No provider publishes its reputation score, which is why diagnosis works by elimination rather than by reading a dashboard.
Our guide on how to reduce your spam complaint rate covers how it’s calculated and how to bring it down.
What Should I Check First When Emails End Up in Spam?
Check authentication first, complaints second, blocklists third, then list quality and content. The order matters. The early checks are fast, free, and cover the largest share of cases.
Work down the list. Stop when you find a failure, fix it, then send again before moving on.
Is Your Email Authentication Passing?
Authentication passes when SPF, DKIM, and DMARC all align with the domain in your From address. A DKIM or DMARC failure sends mail to spam at Gmail and Outlook. Good content won’t rescue it.
Check these 3 records:
- SPF lists the servers allowed to send for your domain
- DKIM signs each message so the provider can detect tampering
- DMARC tells providers what to do when SPF or DKIM fails
Pass signal: spf=pass, dkim=pass, and dmarc=pass in the header above.
Fail signal: any one of the 3 reading fail, none, or temperror.
Our guide on how SPF, DKIM, and DMARC work covers what each record does and how to publish it.
Warning: SPF allows only 10 DNS lookups per check. If you exceed the limit, SPF returns permerror, which fails every message from your domain. Our post on SPF flattening explains how to stay under the limit.
If you send through a provider like SendLayer, you’ll only need to add the DNS records once from your account area. They then apply to every send.
Is Your Complaint Rate Above 0.3%?
Find your complaint rate in Postmaster Tools. Treat anything above 0.3% as the cause until you’ve ruled it out. Complaints outrank almost every other signal, so nothing else you fix will help as long as the rate stays high.
- Pass signal: under 0.10% across 30 days.
- Fail signal: any single day at or above 0.30%.
Complaints climb for 3 main reasons:
- People don’t remember signing up
- Sending frequency jumped without warning
Make unsubscribing the easy option. Adding a List-Unsubscribe header puts a native unsubscribe link in the mail client. That moves people off the spam button.
Is Your Domain or IP on a Blocklist?
Check your sending domain and IP against the major blocklists. One listing can block mail at several providers at once. Listings usually follow a spam trap hit, a compromised account, or a sudden volume spike.
- Pass signal: no listings on the major lists.
- Fail signal: a listing, often paired with bounce messages that name the blocklist.
Our guide on email blacklists covers where to check and how delisting works.
Important: Delisting without fixing the cause gets you listed again. Find the spam trap or the compromised account first.
Is Your List Quality or Sending Volume the Problem?
Poor list quality and sudden volume jumps both read as spam behavior. Old addresses generate bounces and trap hits. A volume spike from a cold domain looks like a hijacked account.
Watch these 4 signals:
- Hard bounce rate above 2%
- Open rates falling while volume rises
- Long gaps between sends, then a large batch
- Purchased or scraped addresses anywhere in the list
Remove addresses that bounce hard, then keep them out with a suppression list. Our guides on hard and soft bounces and warming up a domain cover both sides.
Is Your Content or HTML Triggering Filters?
Content is the last thing to check, not the first. It rarely acts alone. Filters weigh content against your reputation. One email can reach the inbox from a trusted domain and fail from a new one.
Fix the 5 that matter most:
- Add a plain-text version alongside your HTML
- Use your own domain for links instead of a link shortener
- Set a real reply-to address that accepts mail
- Keep the HTML clean and close every tag
- Replace attachments with links
Our list of spam trigger words covers the wording side. Reputation still outweighs word choice in every modern filter.
Why Transactional Emails Go to Spam
Transactional emails go to spam for different reasons than marketing emails. They’re triggered one at a time, so they never build the engagement history that filters look for.
Here are four common causes for transactional emails ending in spam:
- No engagement history per message type. A password reset is sent rarely, so it provides almost no positive signal.
- Missing reply-to. Mail from
no-reply@with no working inbox reads as automated bulk mail.
Separate the streams. Send transactional mail from a dedicated subdomain. A marketing complaint then can’t take down your password resets.
The good news is that SendLayer automatically routes your transactional emails through a subdomain. This protects your actual domain from a bad IP reputation and other spam complaints.
Note: Google’s one-click unsubscribe rule covers marketing and subscribed messages, not transactional mail. A receipt doesn’t need an unsubscribe link. Adding one to a password reset creates a support problem.
Our guide on transactional email covers how these sends differ from campaigns.
What if Everything Passes and Mail Still Goes to Spam?
If authentication passes, complaints are low, and you’re not blocklisted, the cause is usually recipient-side or provider-specific. That narrows the problem considerably.
Check these four areas in order:
- One provider only. Gmail is fine, and Outlook failing points to a provider-specific filter, not your setup. Our guide on Outlook deliverability covers that case.
- Recipient-side rules. Corporate mail servers add their own filters on top of the provider’s. A single company blocking you isn’t a domain problem.
- The From name and domain changed recently. A new sending domain has no history, so early mail gets filtered while trust builds.
- The recipient’s own behavior. Someone who deleted your last 10 emails without opening them has taught their provider to hide the next one.
Note: New domains are filtered more often, which is expected. Volume and consistency fix it over weeks, not settings changes. To learn more, see our guide on warming up your new domain.
How Long Does It Take to Get Out of the Spam Folder?
Authentication fixes work within hours. However, if the issue is due to a bad IP reputation, it takes 2 to 6 weeks of consistent sending to undo it. The split tells you whether to expect a quick or slow recovery.
Here’s what to expect by cause:
| What you fixed | Typical recovery | Why |
|---|---|---|
| SPF, DKIM, or DMARC | Hours to 2 days | Providers re-check DNS on the next send |
| Blocklist listing | 1 to 7 days after delisting | Delisting propagates, then trust returns |
| Complaint rate | 2 to 6 weeks | Providers average complaints over a rolling window |
| Domain reputation | 4 to 8 weeks | Rebuilt only by sending mail people engage with |
Keep volume steady while you recover. If you pause sending, it removes the positive signals you need. A large catch-up batch afterward restarts the damage.
Our guide on domain reputation covers how providers build and update that score.
Frequently Asked Questions
These are answers to some of the top questions we see about understanding why emails end up in spam.
How do I stop my emails from going to spam?
Fix authentication first, then bring your complaint rate under 0.3%. Those 2 steps resolve most cases. After that, clean your list, keep sending volume steady, and add a plain-text version to every HTML email.
Why do my emails go to spam for some recipients but not others?
Because filter thresholds are set per recipient, not per sender. Someone who opens and replies to your mail trains their provider to trust you. A recipient who ignores it teaches the same provider the opposite. Identical messages then land differently.
Do transactional emails go to spam too?
Yes, and often for reasons campaigns don’t share. Transactional mail sends one message at a time, so it builds little engagement history. Shared IPs, missing reply-to addresses, and mixing transactional mail with marketing mail on a single domain are the usual causes.
Does a high image-to-text ratio send emails to spam?
Not on its own. Modern filters weigh sender reputation far more heavily than image ratios. An image-heavy email from a trusted domain reaches the inbox. The same design from a new domain with complaints doesn’t.
That’s it! Now you know why your emails go to spam and how to fix it.
Next, would you like to learn about the differences between email bounces? Check out our tutorial on hard vs soft bounce for more information.
