Your emails are landing in spam because you're doing something wrong. Not because Gmail hates you. Not because the algorithm is broken. Because you're making mistakes that are completely fixable. Start with email authentication, then check your sender reputation.
Inbox providers like Gmail and Yahoo aren't out to get you. They're protecting their users from the 45% of daily emails that are actual spam. Your job is to prove you're not one of those senders.
You do that with three things: technical setup, good content, and an engaged list. Miss any one of these and you're toast.
Why Your Emails Are Landing in Spam
Stop blaming the algorithm. Start looking at what you're actually doing wrong.
Gmail, Yahoo, Outlook. They all use sophisticated filters. These filters are judging you on three things:
- Your technical setup. Do you have SPF, DKIM, and DMARC configured? No? You look like a scammer.
- Your content. Are you using spammy words, broken links, or images without alt text? Red flags everywhere.
- Your engagement. Are people opening your emails? Clicking? Or deleting without reading? Providers notice.
When one of these fails, your sender reputation tanks. And once your reputation is in the toilet, everything you send looks suspicious.
Think of it like a credit score for email. Bad behavior compounds. Good behavior takes time to rebuild.
The good news? You can fix all of this. Let's start with the technical stuff.
Set Up Your Authentication (This Is Non-Negotiable)
I don't care how good your emails are. Without proper authentication, you're sending from an unverified address. That's like showing up to a job interview without ID.
You need three things set up in your DNS. No exceptions.
SPF (Sender Policy Framework)
This tells inbox providers which servers are allowed to send email on your behalf. Without it, anyone could pretend to be you.
It's basically a list that says: "These IP addresses can send email for my domain. Everyone else is an impostor."
DKIM (DomainKeys Identified Mail)
DKIM adds a digital signature to your emails. It proves the message wasn't tampered with in transit.
Think of it as a wax seal on a letter. If the seal is broken, something's wrong.
DMARC (Domain-based Message Authentication)
DMARC is the bouncer. It tells receiving servers what to do when SPF or DKIM fails. Reject the email? Quarantine it? Just monitor?
You also get reports showing who's trying to send email from your domain. Useful for catching spoofers.
Here's the thing. Setting these up usually takes about 30 minutes. You're adding text records to your DNS. Your email provider has step-by-step guides. There's no excuse not to do this.
Want to check if you're set up correctly? Use a free tool like MXToolbox or dmarcian's inspector. Takes 10 seconds.
If you're not authenticated, fix that today. Everything else I'm about to tell you won't matter until you do.
Write Content That Doesn't Trigger Spam Filters
Your technical setup is perfect. Great. Now let's talk about what you're actually sending.
Spam filters scan everything. Your subject line. Your body copy. Your links. Your images. They're looking for patterns that match what spammers do.
Here's how to not look like a spammer.
Subject Lines That Don't Scream "Spam"
Stop using all caps. Stop with the "🔥🔥🔥 LAST CHANCE!!! 🔥🔥🔥" nonsense.
You know what works? Being clear about what's inside.
Bad: "OPEN NOW FOR A HUGE SURPRISE!!!" Good: "Your February order ships tomorrow"
See the difference? One sounds like a used car salesman. The other sounds like a real business.
Keep your subject lines honest. Create curiosity without being clickbait. That's it.
Balance Your Images and Text
Spammers love sending emails that are just one giant image. Why? Because they can hide text from filters that way.
So spam filters are suspicious of image-heavy emails. Keep yours at least 60% text, 40% images max.
And for the love of all things good, add alt text to every image. If someone's email client blocks images by default, they should still understand what your email is about.
Watch Your Links
Every link in your email is being analyzed. Some types are massive red flags.
URL shorteners like bit.ly? Spammers use these to hide malicious destinations. Filters hate them. Use full URLs.
Broken links? They make you look sketchy. Check every link before you send.
Too many links? Pick 2-3 max. You're writing an email, not a Wikipedia page.
Missing unsubscribe link? That's illegal in most places. And when people can't unsubscribe, they hit "spam" instead. Guess what that does to your reputation.
For more on crafting emails that convert, check out our guide on email design best practices.
Your Email List Is Probably a Mess
Here's the truth nobody wants to hear. A big list means nothing if half of it is dead weight.
Every time you email an inactive subscriber, you're hurting yourself. They don't open. They don't click. Inbox providers notice. Your reputation drops.
And if you're emailing addresses that don't exist? Even worse. Hard bounces are reputation killers.
Stop Buying Lists
I shouldn't have to say this in 2026. But people still do it.
Buying email lists is the fastest way to destroy your deliverability. Those people never asked to hear from you. They're going to mark you as spam. Guaranteed.
Build your list the right way. One subscriber at a time. If you need help, here's how to build an email list that actually converts.
Use Double Opt-In
When someone signs up, send them a confirmation email. They click a link to confirm. Now you know two things:
- The email address is real (no typos)
- They actually want to hear from you
Yes, it adds friction. Yes, you'll get fewer signups. But the people who confirm are worth 10x more than the ones who wouldn't have.
Clean Your List Regularly
You need a system for removing dead weight. Here's what to purge:
Hard bounces: Remove immediately. These are dead addresses. Your email platform should do this automatically, but verify it's working.
Inactive subscribers: Anyone who hasn't opened or clicked in 90-120 days needs to go. I know it hurts to watch your list shrink. Do it anyway.
Spam complainers: If someone marks you as spam, they're gone. Forever. Don't email them again.
A list of 5,000 engaged subscribers will outperform a list of 50,000 ghosts every single time.
The Rules Keep Changing (Stay Current)
In 2024, Google and Yahoo rolled out strict new requirements for bulk senders. If you send more than 5,000 emails a day, you're held to a higher standard.
That means mandatory SPF, DKIM, and DMARC. That means keeping spam complaints below 0.1%. That means one-click unsubscribe.
Break these rules and you won't just land in spam. You'll get blocked entirely.
Apple's Mail Privacy Protection Changed Everything
Here's something that messes with a lot of marketers. Apple's Mail Privacy Protection pre-loads email content. That means every email looks like it was opened, even if the person never saw it.
So if you're still obsessing over open rates, you're looking at broken data.
Focus on what actually matters:
- Click-through rates. Did they click something? That's real engagement.
- Replies. Someone replying to your email is one of the strongest positive signals possible.
- Conversions. Did they buy, sign up, or download? That's the whole point.
Open rates are vanity. Clicks and conversions are reality.
Monitor Your Reputation
Use tools like Google Postmaster or Microsoft SNDS to see how inbox providers view you. If your reputation is dropping, you'll know before things get critical.
Check your domain against blacklists regularly. MXToolbox makes this easy. If you're on a list, you need to fix whatever caused it and request removal.
Quick Fixes You Can Do Today
Overwhelmed? Here's your priority list. Start at the top.
| Action | Why It Matters | Do This First |
|---|---|---|
| Set up SPF, DKIM, DMARC | Without authentication, you look like a scammer | Yes |
| Remove hard bounces | Dead addresses tank your reputation | Yes |
| Add unsubscribe link | Legal requirement, prevents spam complaints | Yes |
| Clean inactive subscribers | Low engagement hurts your sender score | Soon |
| Stop using URL shorteners | Filters treat them as suspicious | Soon |
| Balance images and text | Image-only emails look spammy | Soon |
Do the first three today. The rest can wait until next week. But don't wait longer than that.
Common Questions About Email Deliverability
Why did my emails suddenly start going to spam?
Something changed. Find out what.
Did you blast a huge campaign after being quiet for weeks? That spike in volume looks suspicious.
Did your spam complaint rate jump? Check your last campaign's report.
Did you add a new link or change your email template? Small tweaks can trigger filters.
Check if your domain is blacklisted. Use MXToolbox. If you're on a list, you need to fix the problem and request removal.
Don't panic. Investigate. Find the trigger. Fix it.
How often should I clean my email list?
At minimum, every six months for a deep clean. But some things need to happen more often:
- Hard bounces: Remove immediately after every send
- Spam complaints: Remove immediately
- Inactive subscribers: Set a 90-120 day sunset policy
If you're a high-volume sender, waiting six months is way too long. Set up automation to handle this continuously.
For more on keeping your campaigns healthy, check out our guide on email campaign performance metrics.
Should I get a dedicated IP address?
Maybe. It depends.
Get a dedicated IP if:
- You send 50,000+ emails per month
- You send consistently (not huge gaps between campaigns)
- You want full control over your reputation
Stick with shared IP if:
- You're lower volume
- You send sporadically
- You don't want to manage IP warm-up
Here's the catch with dedicated IPs. You start with zero reputation. You have to gradually warm it up over weeks. Send too much too fast and you're flagged immediately.
A well-managed shared IP from a reputable email provider often performs better than a poorly managed dedicated one.
My open rates tanked overnight. What happened?
First, check if it's actually a problem or just bad data. Apple's Mail Privacy Protection inflates open rates for Apple Mail users. If your audience skews toward iPhone users, your data is noisy.
If it's a real drop:
- Check if you hit a blacklist
- Look at your recent spam complaint rate
- Review any recent changes to your sending patterns
- Make sure your authentication is still working
Sometimes ISPs have temporary issues too. Wait 24-48 hours before assuming the sky is falling.
Stop Making These Mistakes
Let me leave you with the biggest mistakes I see:
- No authentication. Fix SPF, DKIM, DMARC today. Not tomorrow.
- Buying lists. Just stop. Build your list properly.
- Ignoring inactive subscribers. They're dragging you down. Let them go.
- Using spam trigger words. "FREE!!! ACT NOW!!!" makes you look like every scammer ever.
- No unsubscribe link. Illegal and stupid. When people can't unsubscribe, they mark you as spam.
- Image-only emails. Filters hate them. Balance your content.
- Obsessing over open rates. Focus on clicks and conversions. That's what matters.
Fix these and your deliverability will improve. I've seen it happen hundreds of times.
Email marketing still works. It works incredibly well when you do it right. The average ROI is still 36:1. But only if your emails actually reach the inbox.
Now go check your authentication settings.
Tired of fighting the spam folder? At Inbox Connect, we handle email deliverability so you don't have to. From authentication setup to list management to automated campaigns that convert. Book a free 30-minute email audit and get a roadmap to fix your deliverability for good.