How to stop emails from going to spam Gmail sends them to: find the reason first, then fix authentication, complaints, sending pattern and content in that order.

How to stop emails from going to spam Gmail sends them to

Almost everyone who looks up how to stop emails from going to spam Gmail sends them to starts by rewriting subject lines. That is the last thing to change, and usually the least useful.

Spam placement is a symptom. Underneath it sits one of a small number of causes, and most of them announce themselves in places you can read in twenty minutes: the headers of a delivered message, the response your sending server got, and your Postmaster Tools dashboards.

So the order on this page is diagnosis first, fixes second. Work through it top to bottom and you will know which cause you have before you touch the copy.

Why do my emails go to spam? The seven causes

When people ask why do my emails go to spam, the honest answer is that a filter weighed several signals and decided your message looked unwanted. The signals are not secret, and providers publish most of them.

• Authentication failures: SPF, DKIM or DMARC did not pass, or the From domain is not aligned with the domain that authenticated.
• Complaint rate: enough recipients pressed the spam button that you crossed a published threshold.
• Reputation: the sending domain or IP address has a history the provider already distrusts.
• List quality: invalid addresses, people who never opted in, or contacts who have not opened anything in months.
• Volume and pattern: a new domain, a sudden spike, or bursts instead of a steady rate.
• Content and links: the message itself, which Google lists as a delivery error reason but well below the others.
• The recipient: their own filter, a block, an unsubscribe they clicked, or a policy their administrator set.

Notice how few of these are about writing. Six of the seven are infrastructure, list and behavior.

What spam filters actually weigh

Google gives one sentence that explains the whole ranking. Gmail combines user reports and other signals, with authentication information, when classifying messages. Reports from recipients come first in that sentence, and the text of your email is not in it at all.

That is why engagement matters more than wording. Yahoo warns that sending to recipients who do not read your email harms your delivery metrics and reputation, and Google suggests unsubscribing people who never open your messages.

• Recipient reports: the spam button, which providers count as a rate rather than a total.
• Authentication: a pass or fail on SPF, DKIM and DMARC, plus alignment of the visible From domain.
• Sender history: what your domain and IP address have sent before, which is why a free sending address gives filters nothing to trust.
• List behavior: bounces, invalid addresses and recipients who never open anything you send.
• Unsubscribe handling: whether people can leave in one click and whether you honor it quickly.
• Message signals: subject lines, links, attachments and mixed content types, weighed last of the group.

None of the three providers publish a scoring formula, and anyone who quotes one is guessing. What they do publish are requirements and rates, and those are the parts you can act on.

The diagnosis order that saves you a week

Each step below either names the cause or rules it out. Do not skip forward, because a content change made while DKIM is broken teaches you nothing.

The table below turns the symptom you can see into the place to look next.

Step one: read a delivered message yourself

Send the exact campaign email to an account you own at Gmail, then open it and choose Show original. Google documents this path, and also offers the Admin Toolbox Messageheader tool for pasting a raw header in.

You are looking for three lines: SPF, DKIM and DMARC, each with a pass or a fail. Gmail also shows a quicker signal in the message itself. Google states that a question mark next to the sender name means the message was not authenticated.

Two traps are worth knowing. Google notes that authentication alone does not guarantee delivery, because spammers authenticate too. And Google warns that a forwarded message which previously failed authentication is treated as unauthenticated, even if it passes now.

Step two: the code already names the cause

Your sending platform logs the response Gmail gave. Google publishes what each enforcement code refers to, and these are the ones that appear when a sender requirement is not met.

The pattern is easy to remember. A 4.7.x code is a temporary rate limit and a warning. A 5.7.x code is a block. Both name the requirement you failed, which is more than any content guess will give you.

Google also describes a separate rate limit case. When your domain or IP sends at a suspiciously high rate, the advice is to stop sending immediately, resume a few minutes later, and keep the rate constant rather than variable.

Step three: checking Postmaster Tools

Google Postmaster Tools is the only scoreboard Gmail gives senders. Add the domain you authenticate with, verify it by DNS record, and Google says verification usually happens immediately but can take up to ten minutes to show.

Once data appears, four dashboards matter for a spam placement.

Two limits are important. Google states that the data covers only messages sent to personal Gmail accounts, and that data may be missing on days when your volume is too low to report without exposing individual users.

One more change is worth planning for. Google has said the Domain and IP Reputation dashboards are being retired in the new Postmaster Tools, in favor of a compliance view, because reputation data was slow to move and hard for most senders to act on.

The delivery error names Google publishes

The delivery errors dashboard groups problems by cause, and the names are unusually direct. Suspected spam, email content is possibly spammy, bad or unsupported attachment, DMARC policy of the sender domain, sending IP or domain has a low reputation, listed in public blocklists, and bad or missing PTR record.

Each one comes with an action. For a missing PTR record Google points to the Admin Toolbox Dig tool. For blocklist entries it tells you to contact the organization that listed you and ask to be removed.

Fixing authentication failures

This is the first fix because nothing below it works while it is broken. Google requires SPF or DKIM for every sender, and SPF, DKIM and DMARC for bulk senders, which it defines as close to 5,000 messages or more to personal Gmail accounts in 24 hours.

• SPF: one record, listing every service that sends for the domain, and inside the DNS lookup limit your provider enforces.
• DKIM: a working selector in DNS. Google requires a key of 1024 bits or longer for mail to personal Gmail accounts.
• DMARC: a published record with a policy. Google accepts p=none, and Microsoft asks for at least p=none aligned with SPF or DKIM.
• Alignment: the domain in the visible From header must match the SPF or DKIM domain. This is what 4.7.32 is about.
• Reverse DNS: valid forward and reverse records for sending domains or IPs. Yahoo adds that PTR records should be meaningful and not generic.
• TLS: Google requires a TLS connection for transmitting email, and rejects with 5.7.29 when it is missing.
• The rest of DNS: while you are in the zone file, confirm the MX records so replies and bounces reach you.

One detail catches teams that use several platforms. Google's guidance is to give each third party sending service its own DKIM key and configuration, so one vendor's mistake does not pull the whole domain down.

Complaint rate, the number with published limits

Gmail's sender guidelines say to keep the spam rate reported in Postmaster Tools below 0.3%, with 0.10% as the recommended level. The sender FAQ is blunter: stay below 0.1% and never reach 0.3% or higher.

The FAQ also explains the shape of the penalty and the way back. The impact is graduated, bulk senders above 0.3% are not eligible for mitigation, and eligibility returns when the rate stays below 0.3% for seven consecutive days.

Yahoo asks for the same 0.3% ceiling and runs a Complaint Feedback Loop that sends you a copy of each complaint once your mail is DKIM signed. Microsoft publishes no number and lists hygiene practices instead.

The arithmetic is unforgiving at small volumes. One complaint on a day when you sent two hundred emails is well above 0.3% for that day, which is an argument for sending to people who expect your mail.

Content and link patterns, honestly ranked

Content is on the list, just not at the top. Google's delivery error descriptions include one for content, and note that some types of content, such as internet links, increase the chance a message is treated as spam.

• Links: few of them, on domains you control, and not a bare shortened link that hides where it goes.
• Attachments: Google rejects unsupported attachment types outright, so link to a file instead of attaching one.
• Mixed purposes: Google's guidelines tell senders not to mix content types, for example promotions inside a receipt.
• Headers that mislead: Microsoft asks for accurate subject lines and no deceptive headers. Your email subject lines should describe the message honestly.
• A From address that works: Microsoft asks that the From or Reply-To address be valid, reflect the sending domain and accept replies.
• Sender domain: sending business mail from a free email domain removes the one thing you can build reputation on.

What is not on any provider's published list is a vocabulary of forbidden words. Filters weigh behavior far more heavily than adjectives, and a clean message from a distrusted domain still lands in spam.

New domains and volume spikes

A new domain has no record, and providers treat absence of history carefully. Google defines a new domain precisely: one that has not sent more than 5,000 emails a day to personal Gmail accounts since January 1, 2024.

Google's advice for that situation is consistent. Start with a low volume to engaged users, raise it slowly over time, send at a consistent rate, avoid bursts, and avoid sudden spikes if you have no history of large volumes.

Spikes hurt established domains too. A quiet domain that sends one email blast to a large list looks, from the outside, exactly like a compromised account. If you are setting up a new sending domain, our email warm up guide covers the ramp in detail.

One more piece of Gmail trivia matters for planning. Bulk sender status is counted across a primary domain and its subdomains, and once a sender meets the threshold the status does not expire.

List quality and bounce handling

Complaints and bounces both come from the list, and every provider says the same thing about it in different words.

• Send to people who opted in. Google's recommended actions for a high spam rate begin with sending only to recipients who want your messages.
• Confirm addresses before adding them. Google lists confirming each recipient's address as a best practice.
• Remove the unengaged. Google suggests unsubscribing recipients who do not open or read your messages.
• Clean invalid addresses. Microsoft lists bounce management as a hygiene practice, and Yahoo warns that mailing people who do not read your email harms your metrics.
• Use the feedback data. Google suggests adding a Feedback-ID header so you can see which campaigns get reported.
• Keep the record clean. An email marketing database full of addresses nobody verified is the most common hidden cause.

Make unsubscribing easy while you are here. Gmail requires one-click unsubscribe from bulk senders, Yahoo asks that unsubscribes be honored within two days, and both want a visible link in the message body.

Recipient side filters and rules

Sometimes nothing is wrong with your sending, and one company still never sees your mail. Google documents several recipient side reasons, and none of them show up in your dashboards.

The distinction matters. A filter or a block is one recipient's decision, so no amount of DNS work changes it. A missing approved sender entry is an administrator's decision, and a two-line email to their IT contact usually fixes it.

Asking a recipient to whitelist your address

Whitelisting is not a technical trick, it is the recipient teaching their own provider. Google documents exactly what works in Gmail, and both steps are short.

1. Open the message in the spam folder and choose Report not spam. Google states that after the email is removed from Spam, future emails from that sender will not go there.
2. Add the sender to Google Contacts. Google states that Gmail then stops sending that sender's messages to Spam.

For a work account, the equivalent lives with the administrator. Google's admin documentation describes approved sender lists whose incoming messages bypass Gmail spam filters, with the warning that such a list should contain trusted senders only.

The template further down is written for this request. Keep it short, tell them exactly which two buttons to press, and give them a way out in the same message.

Spam folder or Promotions tab?

These get confused constantly, and the fix for one is not the fix for the other. Promotions is an inbox category, described by Google as deals, offers and other promotional email. The recipient can still open it.

Spam is a separate folder for mail Gmail treats as unwanted. If your mail reaches Promotions, deliverability is working. If it reaches Spam, one of the causes above is active.

Google also notes that a recipient can move a message to the right category, and that tab placement is theirs to adjust. Treat Promotions as a marketing question, not a deliverability failure, and keep your email marketing campaigns honest about which they are.

What each provider does when you fail

The three big consumer providers publish different enforcement, which is why placement can differ by inbox on the same send.

Microsoft's requirements apply to domains sending more than 5,000 emails a day to hotmail.com, live.com and outlook.com consumer addresses. Microsoft also reserves the right to filter or block non-compliant senders outside that threshold.

What to do after a spam placement

The instinct is to send more, to a wider list, to make up the lost replies. That is the one move that reliably makes it worse.

1. Pause the campaign. Google's guidance for a rate limit is to stop immediately and resume slower, and the same logic applies to a spam placement.
2. Fix the specific cause the diagnosis named, not everything at once, so you can tell what worked.
3. Send only to people who reply, at a steady rate, for several days.
4. Watch the spam rate. Google says to allow up to seven days after corrective action for the rate to settle into compliance.
5. If you are a bulk sender above 0.3%, keep it under that for seven consecutive days to become eligible for mitigation again.
6. Only then rebuild the campaign, and keep the rebuilt version smaller than the one that broke.

Recovery is slow because reputation is slow. Google's own reason for retiring the reputation dashboards was that changes in sender behavior are slow to reflect there, which tells you something about the timescale.

How to stop emails from going to spam in Gmail

1. Get a delivered copy and read its headers

   Send to an account you own at Gmail, open Show original, and note whether SPF, DKIM and DMARC each passed and whether the From domain aligns.

2. Read the SMTP response your platform logged

   A 4.7.x code means rate limiting, a 5.7.x code means a block, and Google publishes what each one refers to. The code names the cause for you.

3. Open Google Postmaster Tools for the sending domain

   Check the compliance, authentication, delivery errors and spam rate dashboards before you form a theory about content.

4. Fix authentication and DNS before anything else

   Correct SPF, DKIM, DMARC alignment and the PTR record. Nothing else you change matters while messages fail authentication.

5. Cut volume and clean the list

   Stop sending to addresses that never open, remove invalid ones, and return to a steady rate instead of bursts.

6. Change content and links last, then wait

   Simplify links and attachments, keep sending to people who reply, and give the spam rate several days to settle before judging the result.

Consent, unsubscribes and the law

Deliverability and the law point the same way, which is convenient. In the United States, the FTC says an opt-out mechanism must work for at least 30 days after you send, and that you must honor a request within 10 business days.

The FTC also requires a valid physical postal address in commercial email, which can be a street address, a registered post office box, or a private mailbox. Yahoo asks that unsubscribes be honored within two days, which is stricter than the law.

If you send cold email, read the rules for your recipients' countries as well. Several require consent before the first message, not just an easy way out afterwards.

What to watch every week

Run this on the same day each week so the readings compare. A steady sales cadence is easier to diagnose than a schedule that changes every campaign.

Common mistakes when emails go to spam

• Rewriting subject lines before checking whether the message authenticated at all.
• Reading a delivery rate near 100 percent as proof of inbox placement, when every message went to spam.
• Changing five things at once, so the fix that worked stays unknown.
• Ignoring the SMTP code because it looked like a technical detail, when it named the requirement.
• Treating a Promotions tab placement as a spam problem and rebuilding a working campaign.
• Sending harder to make up lost replies, which raises complaints on the same list that caused them.
• Asking every recipient to whitelist you instead of fixing the cause, which annoys people who did nothing wrong.
• Expecting reputation to recover in a day when the providers describe it as slow to move.

Most of these come from the same root: acting before the diagnosis. Our outreach tips cover the sending habits that keep you out of this position.

The email that asks a recipient to whitelist you

This example was written for this page. It is for a contact who expects your mail, has replied before, and has now gone quiet because your messages stopped reaching their inbox.

Subject: Found my last email in spam?

Hi {{firstName}},

I sent you a note on {{date}} about {{topic}} and it may have landed in your spam or junk folder rather than your inbox.

If it did, two things fix it on your side for good: open the message and choose Report not spam, then add {{senderAddress}} to your contacts. Gmail stops filtering a sender once you do both.

If you would rather not hear from me at all, reply with the word stop and I will remove you today.

{{senderName}}

Frequently asked questions