How to Stop Your Emails Going to Spam

You wrote the email, you sent it, and nothing came back. Before you rewrite a word, check that it reached the inbox at all, because a sixth of ordinary business email does not, and nearly all of that lost email is avoidable.

The rules for reaching the inbox are not guesswork. Google, Yahoo and Microsoft all published exactly what they require of bulk senders and when they started enforcing it.

Aim for 95% of your emails reaching the inbox, because the 83.5% average includes careless senders

The 83.5% global average of email reaching the inbox is not a floor you are stuck with.

• Senders with a good reputation get 95% or more of their email into the inbox, but senders with a damaged reputation fall to 50% or lower. Almost all of the gap between a good and a damaged sender reputation is something you control.
• In 2024, 83.5% of email worldwide reached the inbox, 6.7% went to the spam folder and 9.8% was blocked before reaching either. Validity, an email software company, measured those 2024 figures with test addresses at hundreds of email providers.
• More mail is blocked outright than is filed in spam, and blocked mail never reaches any folder the reader could fish it out of.
• No sender gets 100% of their email into the inbox, but treat anything below about 95% reaching the inbox as your own doing.
• Your own sending tool will report an email that went to the spam folder as delivered. "Delivered" in a sending tool only means the receiving server accepted the message.

Set up SPF, DKIM and DMARC on your sending domain, or Microsoft will refuse your mail outright

Setting up SPF, DKIM and DMARC is a one-time job.

• Google and Yahoo made SPF, DKIM and DMARC compulsory for bulk senders on 1 February 2024, and Microsoft followed on 5 May 2025.
• Google, Yahoo and Microsoft apply these SPF, DKIM and DMARC rules once you send about 5,000 messages a day to their own users. Nothing warns you when you cross the 5,000 messages a day line.
• Microsoft refuses bulk mail that fails SPF, DKIM or DMARC, rather than filing it in junk. Microsoft’s rejection comes back as 550 5.7.515 Access denied, a code that means authentication rather than anything you wrote.
• A reader can rescue an email from the junk folder, but nobody can rescue an email Microsoft rejected, so check your mail to Microsoft first.

Make your From address match the domain that passed SPF or DKIM, where most setups fail

SPF, DKIM and DMARC are three short lines of text you add to your domain settings once.

• SPF is a list of the servers allowed to send mail using your domain.
• DKIM is a signature added to every message, which proves the message was not altered on the way.
• DMARC tells receivers what to do when SPF and DKIM fail. A DMARC policy of "none" satisfies every current requirement without blocking anything.
• The address in your From line must match the domain that passed SPF or DKIM, a match called alignment. You can have SPF, DKIM and DMARC records in place and still fail on alignment.

Keep spam complaints below 0.30% of the emails you send to Gmail, or Google will block your domain

The spam complaint rate gets more sending domains blocked than any other single cause.

• Google tells you to keep spam complaints below 0.10% of the emails you send and never to reach 0.30%. A 0.30% spam complaint rate is three complaints in every thousand emails.
• You can watch your own spam complaint rate for free in Google Postmaster Tools, Google’s dashboard for senders. Most senders who get blocked by Gmail never checked Postmaster Tools.
• A complaint is one person pressing the spam button, so buying an email list is the fastest way to cross Google’s 0.30% limit.
• Google’s spam complaint limit is a rate, not a count, so a small careless send hurts as much as a large one.

Find out which email provider is sending you to spam before you blame your writing

The same email sent to two people at different email providers can reach one inbox and fail at the other, for reasons that have nothing to do with what you wrote.

• Microsoft is the hardest of the big four email providers to reach, letting 75.6% of messages into the inbox.
• Gmail is the easiest of the big four email providers to reach, letting 87.2% of messages into the inbox. Yahoo let 86.0% of messages into the inbox. Apple let in 76.3%.
• The same email sent to a list full of Outlook addresses will look worse than when it is sent to a list full of Gmail addresses. Work out which email provider is failing before you change a single word of your email.
• Europe is the strongest region, with 89.1% of email reaching the inbox.

Check Gmail and Microsoft separately, because each keeps its own opinion and neither tells the other

There is no single sender score that every email provider reads.

• Gmail, Microsoft and Yahoo each keep their own opinion of you as a sender, worked out by their own filter. Nobody publishes one universal sender score.
• The same email on the same day can reach the inbox at Gmail and be refused at Microsoft.
• Google Postmaster Tools shows only Gmail's view of you, and Microsoft SNDS, Microsoft's own sender dashboard, shows only Microsoft's. No single dashboard covers both Gmail and Microsoft.
• Fixing a delivery problem at one email provider does not fix it at another. Repairing your Gmail spam rate does nothing for an Outlook rejection.

Look yourself up on a blocklist, because a listing hurts you at every provider instead of only one

• SPF, DKIM and DMARC are one shared standard, so fixing them once fixes them for every provider.
• Blocklists such as Spamhaus are run by independent organisations and read by many email providers, so one listing can hurt you at all of those providers.
• Hitting a spam trap is worse than a high complaint rate, because a trap hit can put you on a blocklist that many providers read, while a complaint rate is one company's opinion of you.
• When every email provider starts failing your mail on the same day rather than just one of them, look yourself up on a blocklist first.

Use Camera to Clipboard to capture a bounce off your phone

Finding out why your email is refused means comparing what you sent with what actually arrived, and the evidence is usually on a phone. Camera to Clipboard, one of my own apps, photographs the phone screen and puts the picture straight onto your computer’s clipboard.

• A Camera to Clipboard photo arrives on your computer’s clipboard the moment you take it, with no cable and no upload. You pair the phone and the desktop once by scanning a code on screen.
• A bounce message such as Microsoft’s 550 5.7.515 error is the single most useful thing to keep when your mail is being refused. A bounce message names the reason for the refusal and the domain involved.
• Camera to Clipboard works for anything on a screen or on paper that would otherwise need a scanner.

Stop rewording your emails to dodge spam filters, because trigger word lists are mostly a myth

Every email guide carries a list of words said to send your email to spam.

• Litmus, which publishes the most-quoted email data there is, states plainly that spam trigger words are mostly a myth. In Litmus’s own words, it now takes more than words to make it into the inbox.
• Spam word lists date from the 1970s and 1980s, when spam filters really did read for language. Spammers learned the spam word lists, so spam filters stopped relying on word lists.
• Modern spam filters weigh your sending domain's reputation, whether you pass SPF, DKIM and DMARC, and how readers behave.
• Changing a word in your email will not save it from a damaged sender reputation, and one word will not sink an email from a healthy one.

Never buy or scrape an email list, because one spam trap address can blacklist your whole domain

Spam traps are addresses that exist only to catch senders using email lists they should not have.

• A pristine trap is an address that never belonged to a real person, so reaching one is near proof of a scraped or bought email list.
• A recycled trap is a real address that was abandoned, left to bounce for months, then switched back on and watched. Hitting a recycled spam trap means you are not removing dead addresses from your email list.
• A single spam trap hit is enough for a Spamhaus listing, and you do not have to be a mass sender.
• Any address on your email list that has not opened or clicked one of your emails in six to twelve months could be a recycled spam trap. Ask those inactive readers once whether they still want your email, then remove the ones who never answer.

Send cold email from a separate lookalike domain, never from the domain your business runs on

Buy separate domains for outreach and keep the address your business runs on out of cold outreach.

• Register near-copies of your company domain and send cold email only from those near-copies. For company.com, a near-copy looks like companyhq.com or company.co.
• Put 2 to 3 mailboxes on each lookalike domain, which works out at about 60 to 90 cold emails a day per domain. Sending 500 cold emails a day needs seven to nine lookalike domains.
• A blacklisted lookalike domain costs you only that lookalike domain, not your company's real email. A blacklisting on your main domain stops your invoices and your replies to customers too.
• Warm up a new domain by sending small, slowly rising numbers of emails for 2 to 4 weeks before sending normally. In the first week of warming up a new domain, send 5 to 10 emails a day.

Do not expect buying a new sending domain to undo a blacklisting you already earned

Buying separate sending domains protects your real address from the start. A new sending domain does not repair a blacklisting you already have.

• A brand new domain has no history, and filters treat no history as a reason for suspicion. New domains get more spam foldering and more rejection in their first weeks.
• Gmail is not linking your new domain to your old one, so the ban itself does not follow you. What follows you to a new domain is the same email list you send to.
• The web address inside your emails keeps its own reputation whatever domain you send from. Spamhaus lists domains found in the body of spam, judged separately from the sender.

Use Repeat Recorder to practise phoning them instead of emailing

Sometimes the person you are emailing is not reachable by email at all, and the next attempt has to be a phone call. Repeat Recorder, another of my own apps, plays your own voice back to you a second after you stop, so you hear how you sound before the person you call does.

• Repeat Recorder plays your recording back about a second after you stop speaking.
• Repeat Recorder’s automatic mode starts recording when you speak and replays when you stop, without you touching the screen.
• In Repeat Recorder you can save the recordings worth keeping into folders you name yourself and loop any of them.

Send 20 to 30 cold emails per mailbox per day, and raise that number by only 10 to 20% a week

• Hold each mailbox to 20 to 30 cold emails a day, and never go past 50.
• Grow your cold email volume by adding mailboxes and domains rather than by sending more cold emails from one mailbox.
• Start a new email account at 10 to 20 emails a day and raise that by 10 to 20% a week, reaching full volume over 4 to 6 weeks.
• Going from 20 emails a day to 200 overnight is the most reliable way to be marked as spam. Email providers watch how your sending volume changes over time, not just today's number.
• The 5,000 emails a day in the Google, Yahoo and Microsoft rules is not a target but the line where SPF, DKIM and DMARC become compulsory. The 5,000 a day line is counted per provider: 5,000 to Gmail users, not 5,000 in total.

Do not confuse your own email host cutting you off with the reader's provider filing you as spam

• Google Workspace lets one user send to 2,000 outside recipients a day and Microsoft allows one mailbox 10,000 recipients a day. The Google Workspace and Microsoft sending caps are per mailbox, not per company.
• Hitting your own email host’s sending cap gets you an error or a suspension from your own provider, and has nothing to do with landing in spam. When you hit a sending cap, your mail never leaves your own provider.
• Adding mailboxes and domains solves a sending cap, but it will not rescue a bad email list.
• Your own provider refusing to send is a sending cap, and the reader's provider filing you in spam is a reputation problem.

Watch your spam complaint rate rather than your daily volume, because the rate is what decides spam

• Each provider scores your domain on complaints, bounces, spam trap hits and whether you pass SPF, DKIM and DMARC. Complaints, bounces and spam trap hits are judged as rates, and SPF, DKIM and DMARC as pass or fail, not as daily totals.
• A 0.30% complaint rate is 0.30% whether you sent 30 emails or 3,000, so sending less does not fix a bad email list.
• Raising your daily sending volume suddenly is itself a warning sign to email providers.
• Each email provider judges only the mail it received from you. If you send 90 emails a day split evenly across Gmail, Outlook and Yahoo, Gmail has seen only 30 of them.
• Keep a domain to about 60 to 90 emails a day so that a mistake stays small while you find out whether the email list is any good.

Clean your email list before sending, because bounces above 2% of sends make the list look bought

A hard bounce is an address that does not exist. Mail providers read your share of hard bounces as a statement about where your email list came from.

• The average hard bounce rate across industries is under 1% of emails sent.
• A hard bounce rate consistently above 2% of sends damages how mail providers score you.
• With a hard bounce rate above 5% of sends, you look like somebody sending to a scraped or purchased email list.
• Checking addresses before you send is the only fix for a high hard bounce rate, and it costs a fraction of a cent per address. Nothing you write in the email can offset a high hard bounce rate.

Do not judge whether you are landing in spam by your open rate, Apple's Mail app breaks it

Watching the open rate stopped working as a delivery check in September 2021.

• Mail Privacy Protection is a setting in Apple's Mail app, not something tied to an icloud.com address. Anyone reading their Gmail or work email in the Mail app on an iPhone or a Mac is covered by Mail Privacy Protection.
• Mail Privacy Protection fetches the invisible tracking image in an email the moment the email arrives, so the sender records an open that never happened.
• Apple's Mail app rendered 62.26% of all recorded opens in July 2026, measured by Litmus across more than a billion opens. Litmus says opens from Apple Mail Privacy Protection users are not reliable opens.
• An open rate that looks healthy can sit on top of a serious delivery problem. To judge delivery, use clicks, replies and Google Postmaster Tools instead of the open rate.

Send yourself a test email at Gmail, Outlook, Yahoo and Apple to see which folder it lands in

Checking which folder your email lands in is free and takes minutes.

• Send the same email to your own accounts at Gmail, Outlook, Yahoo and Apple, then look at which folder it lands in.
• Open Google Postmaster Tools for Gmail, and Microsoft SNDS, Microsoft’s sender dashboard, for Outlook. Postmaster Tools shows your spam rate, whether SPF, DKIM and DMARC are passing, and your delivery errors.
• Treat a sudden drop in replies with nothing else changed as a delivery problem, not a writing one.
• Search your bounce messages for 550 5.7.515, which is Microsoft refusing you outright rather than filtering you.
• Look your domain up on the Spamhaus blocklist. A Spamhaus listing explains every other delivery symptom you are seeing.

Use Camera to Clipboard to keep the folder your test email landed in

A test email to your own accounts only tells you something if you record which folder it landed in. Camera to Clipboard, one of my own apps, photographs the phone screen and puts the picture straight onto your computer's clipboard.

• A photo of the phone showing which folder the test email landed in is the only proof you will have later. Your sending tool will insist the test email was delivered.
• You pair the phone and the desktop once by scanning a code on screen, and after that Camera to Clipboard takes one tap to shoot and one paste to place the photo.
• A repeat test email after a fix is worth nothing unless you can compare the result with what you saw before.

Conclusion: how to stop your emails going to spam

These steps are in order, and the first three decide whether email providers accept your mail at all.

• Add SPF, DKIM and DMARC to your domain.
• Make your From address match the domain that passed SPF or DKIM.
• Keep spam complaints under 0.10% of the emails you send and never reach 0.30%.
• Verify addresses before sending, because hard bounces over 2% of sends mark your email list as bought.
• Remove anyone on your email list who has not opened or clicked in six to twelve months.
• Never buy or scrape an email list.
• Send cold email from a separate lookalike domain, warmed for two to four weeks first.
• Check bounce codes for 550 5.7.515, which is Microsoft refusing your mail, not filtering it.
• Stop rewording your emails to dodge spam filters.
• Hold each mailbox to 20 to 30 cold emails a day, and each domain to 60 to 90.
• Never jump your daily sending volume, and raise it by only 10 to 20% a week.
• Google Workspace’s 2,000 a day sending cap is more than 60 times the safe 30 cold emails a day per mailbox.
• Check your sender reputation at Gmail and at Microsoft separately.
• Send yourself a test email at Gmail, Outlook, Yahoo and Apple.
• Do not trust your open rate, because Apple’s Mail app records most opens automatically.