Vatsal Shah Having your email land in spam can be a real nightmare… especially if it’s your go-to channel for communication and lead generation.
What’s even more frustrating is when you don’t know why your emails are getting flagged—or what you should do to stop it.
It’s a crushing experience, and I know it because this happened to me as well. Back then, I didn’t know much and felt like all my hard work was going to waste.
However, through a lot of research and experimentation, I figured out various factors that can cause your emails to go to spam folders.
In this blog, I’ll share 11 reasons why your emails are landing in spam—and, more importantly, how to fix them so they reach the inbox where they belong.
Keep reading!
Why Are Your Emails Going To Spam – TOC
11 Reasons Why Your Emails Are Going to Spam
If you’re emails are landing in spam, you have to act fast!
So, I’m diving straight into the possible reasons why this is happening:
- Your Authentication Records Are Not Set Up Correctly
- Your Email List Contains Too Many Invalid Addresses
- You Are Sending Non-Personalized Emails
- Your Recipients Are Marking Your Emails as Spam
- You Are Sending Emails in Very High Volumes
- Your Emails Contain Too Many Attachments
- Your Email Content Has Too Many Spammy Words
- Your Emails Have Excessive Links
- Having HTML Scripts in Your Emails
- Your Emails Don’t Include an Unsubscribe Link (Violating Compliance Rules)
- You Are Using a Shared IP Address (Blacklist Risk)
Some of these factors might surprise you, but understanding them is your first step toward fixing your email deliverability and getting your messages back into the inbox.
1. Your Authentication Records Are Not Set Up Correctly
If you’re sending bulk emails for sales, marketing, or outreach, then this is a step you can’t afford to overlook.
(Causal emailers don’t have to worry about this!)
You see, email service providers, like Gmail, Outlook, etc., use authentication records (SPF, DKIM, and DMARC) to verify if you’re the actual sender of the email.
(Spammers can actually pretend to send emails from your domain.)
Without these records set up properly, you might look very suspicious and untrustworthy to ESPs, so it shouldn’t come as a surprise if your emails are going straight to spam.
Pro Tip: As the first step, always set up your authentication records to show ESPs you are genuinely you!
2. Your Email List Contains Too Many Invalid Addresses
The next critical factor is having invalid email addresses in your email list.
When you send emails to addresses that don’t exist (wrong or inactive), your email will bounce.
A couple ( 2 or 4) of bounces is okay, no issues!
However,
Regular Email Bounces = Spam Filters Alterted = Not A Good Situation 🚨
To avoid this issue altogether, you should always–and I mean ALWAYS–clean your email list and remove invalid email addresses.
Pro Tip: I use platforms like ZeroBounce and MillionVerifier to clean my email list before starting my email campaigns.
3. You Are Sending Non-Personalized Emails
If you’re mass-sending generic emails, there is a very, very high chance you will be seen as a spammer by ESPs.
This is how ESPs think–if you genuinely want to provide value, you would send emails that feel relevant and personalized to the recipient.
If your emails all read the same, ESPs recognize it as low effort and assume you’re sending bulk, non-personalized emails—a common trait of spammers.
Even if your generic emails get past spam filters, your recipients are not going to resonate with them, and they’ll mark your emails as spam, which is the next factor I’ll be covering
4. Your Recipients Are Marking Your Emails as Spam
Continuing from the previous point—getting your emails marked as spam is one of the worst things that can happen!
This is a direct signal to ESPs that you are sending unwanted emails!
The more spam complaints, the worse your sender reputation gets.
Your recipients can mark your emails as spam for various reasons like:
- Your emails are irrelevant to them.
- Your subject line is misleading.
- No clarity in what you have to say.
Your recipients are busy people, so keep your emails short, simple and to the point.
Pro Tip: If you’re getting too many spam complaints, I recommend reviewing your email content, sending frequency, and recipient list.
5. You Are Sending Emails in Very High Volumes
Another factor that ESP spam algorithms are closing monitoring is the number of emails you send and the number of recipients you reach out to.
If you suddenly start sending thousands of emails per day from a new or inactive account, you are going to be marked as spam and even blacklisted!
The solution to this is to be consistent and stay within your sending limits!
Pro Tip: To be on the safer side, I recommend not sending more than 50 emails per account per day (for cold outreach). Plus, warm up your inactive/new email accounts before starting a campaign.
6. Your Emails Contain Too Many Attachments
If you’re noticing too many of your emails going to spam, attachments might be your main problem.
The reason behind this is simple – ESPs usually configure email accounts to ensure that you only receive emails with attachments in your inbox if:
- You, as a sender, are trusted (have a good reputation and authentication records in place).
- The attachment type is safe (common file types like PDFs or images rather than .exe or .zip files).
- The email content doesn’t look suspicious
And there’s a very good explanation for this ESP policy: attachments may contain malware or other malicious content.
What I recommend: Completely avoid sending attachments unless your recipients agree to receive them.
7. Your Email Content Has Too Many Spammy Words
This should be very obvious to you!!
“Emails that have spammy language belong in the spam folder”
How do ESPs know this?
Well, they have algorithms in place that check your emails to detect patterns, phrases, and formatting commonly used by spammers in their emails.
So, avoid spammy words like “Congratulations!”, “Risk-free”, “Act now!”, “Make money fast”, and “100% free” and write as naturally as possible without being pushy.
8. Your Emails Have Excessive Links
I know this might sound crazy, but sometimes, even including simple LinkedIn profile links can get you into the spam folders.
After reviewing ESP policies, I’ve realized they have a good reason for this.
Spammers frequently abuse links, stuffing emails with phishing websites, fake login pages, and deceptive offers.
To counter this, ESPs assume emails with too many links are promotional, unsafe, or outright spam.
Shortened links will raise even more red flags because they hide the actual destination, making ESPs extra cautious.
Personally, I avoid having links of any sort in my outreach emails.
9. Having HTML Scripts in Your Emails
If you’re using too much HTML in your emails, it could be a major reason why they’re landing in spam.
Even I used to rely on HTML scripts, thinking they made my emails look more professional and visually appealing.
But what I didn’t realize was that ESPs are extremely cautious when it comes to emails with heavy HTML formatting.
Why?
Because spammers often send HTML-heavy emails filled with tracking pixels, hidden links, and suspicious code.
Pro Tip: Keep Your cold emails simple and text-based.
10. Your Emails Don’t Include an Unsubscribe Link
One of the most recent compliance requirements by ESPs like Google and Yahoo is the inclusion of Unsubscribe links mandatory for mass email communication.
The reason?
They want to give their users (your recipients) an easy way to opt out of your emails.
It is also beneficial for us as now, instead of reporting our emails for spam, recipients can just unsubscribe from our emails.
It’s a win-win-win situation!
I have kept the most craziest one for last!
Say you are following all the best practices—your authentication records are set up, your email content is clean, and your email list is well-maintained.
You have followed everything by the book, yet your emails are still landing in spam!
The hidden reason – having a shared IP address.
Now, you might be wondering—what is a shared IP address?
Let me explain: When you send emails, they are sent through an IP address assigned by your email service provider (ESP).
If other senders on the same shared IP are sending spammy or low-quality emails, ESPs may flag the entire IP—which means your emails get affected, even if you’ve done nothing wrong!
But don’t worry!!
There is a simple solution for this: Always choose a reputed and trusted email service provider (ESP).
Moreover, I also recommend you use Google Postmaster Tools to monitor your IP reputation and domain reputation.
This gives you proactive insights into whether your emails are being flagged, throttled, or facing deliverability issues.
Next, let me show you how you can completely avoid the spam folder!
How to Stop Your Emails From Landing in Spam?
With all the possible reasons why your emails might be landing in spam, it’s time to cover what you should do to be safe.
Here are a few things I recommend you do:
- Authenticate Your Email Address
- Use Double-Opt-In for Marketing Emails
- Personalize Your Emails
- Track Key Deliverability Metrics
- Use an Email Warm Up Service
- Switch to a Dedicated IP Address
1. Authenticate Your Email Address
First and foremost — setting up your email authentication records.
Here are three authentication protocols you should set up:
- SPF: Sender Policy Framework is a security protocol that protects your email account from email spoofing by authenticating you as a legitimate sender.
- DKIM: Domain-Keys Identified Mail is like a passport for your email account. It verifies that the sender is authorized to send emails and identifies whether an email has been altered during its transmission.
- DMARC: Domain-based Message Authentication, Reporting and Conformance identifies compromised emails and instructs the ESP to quarantine them to minimize the possibility of harm to the recipient.
2. Use Double-Opt-In for Marketing Emails
If you don’t want your recipients to mark you as spam, then a simple solution to this problem is to include an unsubscribe link with your emails, right?
Well, there’s an even better method that can help you obtain consent from your recipients: Double-Opt-In.
Here’s how it works:
When users submit their email account information to your newsletter form, you send them an email confirming whether they want to indeed receive emails from you.
This will give the recipient a chance to review their decision, and help you obtain explicit consent for emailing them.
3. Personalize Your Emails
You now know that generic emails have a higher-than-usual chance of ending up in spam folders.
The best solution? Only send personalized emails to your recipients.
But personalization doesn’t mean just adding their first name at the start of the email. That’s basic and often overused.
Instead, thoroughly personalize your emails to make them feel like they were crafted specifically for the recipient.
4. Track Key Deliverability Metrics
Tracking key metrics such as spam rates, bounce rates, and sender reputation will help you stay informed about the health of your email account.
And once you regularly track your deliverability metrics, you’ll also know when you need to start taking evasive action.
For example, as soon as the spam rate spikes up, it’s time to conduct a deliverability audit and fix the problems you notice.
Pro Tip: Use free tools like Google’s Postmaster Tools to easily track key email deliverability metrics.
5. Use an Email Warm Up Service
Warm-up is very important—especially if you’re using a new email account or haven’t sent emails in bulk before.
Your new email accounts don’t have much trust and credibility (sender reputation) with ESPs.
The best way to change that? Email Warm-Up.
Apart from warming up new email accounts, you can also use automated email warm-up platforms to repair damaged sender reputations.
If your emails started landing in spam due to past mistakes, warming up your account can gradually rebuild trust with ESPs.
6. Switch to a Dedicated IP Address
Lastly, I recommend that you switch to a dedicated IP address if you’ve not done so already.
The infrastructure setup cost is quite high, but the benefits far outweigh the investment—especially if you’re sending high volumes of emails.
It’s the easiest way to ensure that you don’t get in trouble because of someone else’s fraudulent behavior.
Always Land In Inboxes!
You now know why your emails may be landing in spam and how various factors play a critical role in email deliverability.
To recap what I have covered:
- Set up your authentication records.
- Personalize your emails for each recipient.
- Avoid spammy language, links, attachments, and HTML scripts.
- Clean your email list to remove invalid email addresses.
- Include an unsubscribe link in your emails.
- Track metrics like spam complaints, bounce rates, IP reputation, etc., so you can proactively take action.
If your emails are landing in spam, don’t panic—Pause your campaigns immediately and try to diagnose the problem.
I also recommend putting them through automated email warm-up using tools like TrulyInbox to gradually rebuild your sender reputation.
Worst case scenario–your email accounts cannot be salvaged and you have to buy new accounts.
But on the brighter side, you’ll know exactly what to do to prevent this from happening again!
Why Your Emails Are Going to Spam: FAQs
1. What is the most common reason for emails landing in spam?
In my experience, the most common reason for emails landing in spam is a poor sender reputation of your email account. Your email account might have a poor sender reputation for several reasons, including:
- Not properly setting up authentication records
- Recipients marking your emails as spam
- High bounce rates
- Too much spammy language, links, and attachments.
- High sending volume
2. What are spam filters?
Spam filters are software programs that ESPs use to identify, monitor, and block emails. From my research, I found that ESPs use spam filters to block emails that might contain harmful or malicious content targeting recipients.
3. How do spam filters work?
I’ve found that spam filters rely on advanced algorithms and mathematical models to detect spam. One of the most common models used is the Naive Bayes classifier, which helps filters identify patterns in email content, sender behavior, and user engagement.
Spam filters analyze hundreds of factors before deciding whether an email should be placed in the inbox, spam folder, or blocked entirely.
