Why Are My HubSpot Emails Going to Spam (and How To Fix It)

Start Here: Which HubSpot Emails Are Going to Spam?

“HubSpot emails going to spam” is really three different problems, and the fix depends on which one you have.

HubSpot sends mail along separate paths. Marketing Hub emails go out through HubSpot’s own sending infrastructure using your connected domain. Sales Hub sequences and one-to-one emails leave through your connected personal mailbox, your Google Workspace or Microsoft 365 account, and never touch HubSpot’s marketing infrastructure at all. Both cases show up constantly in discussions about HubSpot email deliverability.

That distinction matters because the two paths fail for different reasons and are fixed in different places. Tightening SPF and DKIM on your marketing domain will do nothing for a sales rep whose sequences are landing in spam, because those emails are authenticated by the rep’s own mailbox provider.

Before changing any settings, identify which path is affected. The rest of this guide is organized that way.

Key Takeaways

• Set up SPF, DKIM, and DMARC to authenticate your HubSpot emails properly.
• Regularly clean your email list to reduce bounces and spam complaints.
• Avoid spam trigger words and misleading subject lines in your email campaigns.
• Segment and personalize emails to increase engagement and improve deliverability rates.
• Use HubSpot’s tools to monitor email health and fix spam-related issues quickly.

What Is Email Deliverability in HubSpot?

HubSpot Email deliverability means whether your email reaches someone’s inbox or gets blocked or sent to spam. In HubSpot, this depends on how you send your emails, who you’re sending them to, and how they react. If people often delete your emails without reading or mark them as spam, your sender score drops.

HubSpot tracks your open rates, bounces, and complaints to see how healthy your email list is. A good deliverability rate means more people see your emails. A bad one means your emails may go unseen, even if everything else looks right.

Why HubSpot Emails Go to Spam

Spam filters check every email before it reaches someone’s inbox. They look for signs of spam, like bad links, strange wording, or unknown senders. If your email checks too many boxes, it goes straight to spam.

Here are some common reasons this happens in HubSpot:

• Using a free or mismatched sending domain: Emails from Gmail or Yahoo, or domains that don’t match your website, look suspicious to filters.
• Poor list hygiene: Sending emails to old, cold, or fake contacts increases bounces and lowers trust.
• High bounce, unsubscribe, or spam complaint rates: Too many of these tell filters your emails aren’t wanted.
• Misleading subject lines or spammy content: Subject lines that trick people or include “Buy now!!!” often trigger filters.
• Missing email authentication: Without SPF, DKIM, or DMARC set up, email services can’t tell if your emails are real or fake.

How to Diagnose Which Sending Path Is Failing

Work through these checks in order, and write down what you find before changing anything. Authentication and DNS edits take time to propagate, and changing several things at once makes it impossible to tell what actually worked.

1. Identify the sender

Open the affected email in HubSpot and check whether it was sent from Marketing Hub (Marketing then Email) or from a sequence or individual send in Sales Hub. If your reps are reporting the problem and marketing is not, you are almost certainly on the Sales Hub path.

2. Check the visible sending domain

Look at the From address on a delivered copy. Marketing emails should show your connected email sending domain. Sequence emails will show the rep’s own mailbox address.

3. Inspect the received headers

Open a delivered message and view the original headers. The Authentication-Results line shows the SPF, DKIM, and DMARC outcome for that specific message. A fail or softfail tells you exactly which mechanism is broken, and which domain it belongs to.

4. Test whether the problem is universal or recipient specific

Send to one Gmail address, one Outlook address, and one corporate Microsoft 365 address. Spam placement everywhere points at authentication or domain reputation. Spam placement only at Microsoft usually points at reputation or a recipient organization’s own filtering rules rather than a broken record.

5. Separate the domain from the content

Send the same message body from a different, established domain. If it reaches the inbox, your domain reputation is the problem. If it still lands in spam, the content is.

If you are working through data or sync problems alongside deliverability, our guide to fixing Salesforce integration sync failures follows the same diagnose-before-you-change approach.

Common HubSpot Email Deliverability Mistakes

Even if you have a great message, some mistakes can hurt your chances of landing in the inbox. Here are the most common errors HubSpot users make that lower email deliverability:

1. Using purchased email lists: Buying email lists might seem like a shortcut, but it’s a bad idea. These contacts didn’t ask to hear from you, so they’re more likely to ignore, delete, or mark your emails as spam. HubSpot can also block accounts that use purchased lists.
2. Not warming up a new domain: If you just set up a new domain and start sending lots of emails right away, it raises red flags. Email providers need time to trust your new domain. You should slowly increase the number of emails you send, which is called “warming up” your domain.
3. Over-sending or inconsistent email frequency: Sending too many emails in a short time annoys readers. But sending too few makes them forget who you are. Both can lead to low open rates and high spam complaints. A steady, balanced email schedule builds trust.
4. Ignoring engagement metrics: Open rates, click rates, and bounce rates show how people react to your emails. Ignoring these numbers means you could keep sending emails to people who never open them, which hurts your sender score.
5. Not using personalization or segmentation: Sending the same message to everyone doesn’t work well. People want emails that match their interests. Personalization and list segmentation in HubSpot help send the right message to the right person at the right time.

How to Improve Email Deliverability in HubSpot

Good email deliverability means your emails go to the inbox, not the spam folder. Here’s how you can boost your results in HubSpot:

1. Set up email authentication (SPF and DKIM)

SPF and DKIM are like ID checks for your emails. They show email services that your messages are real. Set these up through your domain settings to build trust.

2. Use a connected domain

Don’t send marketing emails from Gmail or Yahoo. Use your business domain and connect it in HubSpot. This shows you’re a real sender.

3. Clean your email list often

Remove old, fake, or inactive contacts. This helps lower bounce rates and keeps your list healthy. Only send to people who want to hear from you.

4. Use double opt-in

Double opt-in asks contacts to confirm their email before they’re added to your list. This makes sure your contacts are real and interesting.

5. Segment your audience

Not every email fits everyone. Create groups based on interests, behavior, or location. Send the right message to the right group to get better results.

6. A/B test subject lines and content

Try different subject lines and email styles. See what gets more opens and clicks. HubSpot makes testing easy, so you can improve with each send.

7. Monitor performance in HubSpot

Use HubSpot analytics to track opens, clicks, bounces, and unsubscribes. These numbers show what’s working and what needs to change.

Learn More: How to Automate Google Drive File Integration with HubSpot Records

Fixing Sales Hub Sequences and 1:1 Emails

Because these emails leave through a connected personal mailbox, the fixes sit with your mail provider and with sending behavior, not with HubSpot’s marketing settings.

Authenticate the mailbox domain, not just the marketing domain

Sequences are authenticated by the domain of the rep’s mailbox. If your marketing subdomain is configured correctly but your primary corporate domain is not, sequences will still fail. Confirm SPF, DKIM, and DMARC on the domain each rep actually sends from.

Respect mailbox sending limits

Google Workspace and Microsoft 365 enforce their own daily sending caps, separate from anything HubSpot shows you. A new mailbox pushed straight to a high daily volume is treated as suspicious no matter how well it is authenticated.

Warm up new mailboxes and new reps gradually

A mailbox with no sending history that suddenly emails hundreds of cold contacts is the most common cause of sequence emails going to spam.

Reduce links and tracking in cold outreach

Link tracking rewrites your URLs to a redirect domain. On a shared tracking domain with weak reputation, that alone can trigger filtering. For cold sequences, consider turning link tracking off and removing images entirely.

Watch reply rate, not just open rate

Mailbox providers weigh genuine engagement heavily. Sequences that generate no replies train filters to treat the sender as bulk mail.

Keep personal sends personal

If a “1:1” email is really a template sent to 200 contacts, providers classify it as bulk mail coming from a personal mailbox, which is exactly the pattern filters are built to catch.

Deliverability usually sits between marketing, sales, and IT, which is why it can stay broken for months. If nobody clearly owns it at your company, that is a revenue operations problem before it is an email problem.

Avoiding Spam Filters in HubSpot Email Campaigns

Spam filters look for warning signs before letting emails through. Here’s how to avoid those traps in your HubSpot campaigns:

• Write clear, honest subject lines:  Don’t trick readers with clickbait or misleading headlines. Be simple and direct about what’s inside your email.
• Avoid trigger words:  Words like “free,” “guarantee,” and “buy now” often raise red flags with spam filters. Use these words carefully or find better ways to say the same thing.
• Optimize your text-to-image ratio:  Emails with too many images and little text look suspicious. Keep a good balance, enough text to explain your message and images to support it.
• Avoid all-caps and too much punctuation:  Using ALL CAPS or too many exclamation points!!! can make your email look like spam. Write normally and keep punctuation simple.

Link only to reputable sites:  Spam filters check the links in your emails. Make sure your links go to trusted, well-known websites. Avoid broken or suspicious URLs.

Frequently asked questions