You spent hours crafting the perfect subject line, designing a beautiful email template, and segmenting your list with precision. You hit 'Send' on your HubSpot campaign, expecting a rush of opens and clicks... only to see your open rate plummet. Why? Most likely your email landed in spam.
Even with a great platform like HubSpot, your emails can still end up in spam.
If you’ve ever wondered “Why are my HubSpot emails not reaching the inbox?”, you’re not alone. A nd the problem usually comes down to a mix of technical setup, content, and sender reputation.
The good news? Most of it can be fixed. Here’s what you need to know — and the steps you can take right now to make sure your emails actually reach your audience inbox and stay out of spam.
Table of content
TL;DR: Common Reasons HubSpot Emails Go to Spam
How HubSpot Sends Emails (and Why Deliverability Isn’t Guaranteed)
The 6 Most Common Reasons HubSpot Emails Go to Spam
1. Missing or Incorrect Authentication (SPF, DKIM, DMARC)
5. Sudden Sending Volume Increases
6. Lack of Engagement Signals
How to improve your email deliverability in HubSpot
The first thing to understand is this: HubSpot (or any Email Service Provider, or ESP) can only send your email; it cannot guarantee deliverability. Once the email leaves HubSpot's servers, the decision—whether it lands in the Inbox, the Promotions tab, or the Spam folder—is entirely up to the recipient’s mailbox provider (like Gmail, Outlook, or Apple Mail).
What it is: Email authentication proves to inbox providers (like Gmail or Outlook) that your email is legitimate and authorized by your domain. HubSpot recommends setting up SPF, DKIM, and optionally DMARC.
Why it matters: Without authentication, your emails are more likely to be flagged as suspicious and filtered into spam — or rejected entirely.
This is where most businesses fail. If the mailbox provider can’t confirm you are who you say you are, your email is dead on arrival.
The Cause: Your domain’s DNS records aren’t set up or configured correctly. These three records prove your domain’s identity:
✅ How to Fix It:
What it is: Sender reputation is like a credit score for your domain/IP. It’s based on your past sending behavior: bounces, spam complaints, engagement rates, etc.
Why it matters: Internet Service Providers (ISPs) use sender reputation to decide whether to deliver your email to the inbox, spam folder, or not at all.
When you send emails through HubSpot (or most email platforms), you're usually using a shared IP, which means your deliverability is partly influenced by the behavior of other HubSpot users on the same IP. While HubSpot actively monitors and manages these IPs to keep reputation high, poor practices by others can still impact your results. If you’re sending high volumes or running critical campaigns, consider upgrading to a dedicated IP to gain full control over your sender reputation.
✅ How to Fix It:
Poor list quality is one of the main reasons HubSpot emails land in spam.
If your contact list hasn’t been cleaned or verified in a while, your emails might end up in spam — even if your content looks great.
Using bought lists is the worst thing you can do. Those contacts never opted in, and many addresses could be fake or inactive. By sending to them you risk hitting spam traps, which can seriously harm your sender reputation and make future emails harder to deliver.
The good news: HubSpot automatically removes hard bounces and stops sending to those addresses to protect your domain reputation.
Still, it’s up to you to keep your list healthy.
Here’s how to stay safe:
A clean, verified list keeps your emails landing in the inbox — and helps HubSpot’s deliverability tools work exactly as they should.
What it is: Certain keywords, formats, and design practices can trigger spam filters — even if your intentions are good.
Why it matters: Spam filters analyze email structure, language, and HTML. Poor formatting or spammy phrases are red flags.
✅ How to Fix It:
💡 Tip: HubSpot’s drag-and-drop editor keeps your code clean, but always preview and test before sending.
Sending too many emails at once, especially to new or large lists, can trigger spam filters. ISPs see sudden spikes in volume as suspicious behavior.
How to avoid it: start by emailing your most engaged contacts first and gradually increase your sending volume over several days or weeks. This “warm-up” approach protects your sender reputation and improves deliverability.
What it is: Gmail and other providers monitor how recipients interact with your emails — opens, clicks, replies, or deletes.
Why it matters: If engagement is low over time, inbox providers may deprioritize your emails or mark them as spam.
✅ How to Fix It:
Follow this checklist to prevent spam issues and improve email deliverability:
Keep in mind these important indicators:
| Bounce rate | (<1%) |
| Unsubscribe rate | (<0.3%) |
| Spam reports | (<0.1%) |
Landing in spam isn’t a HubSpot problem — it’s a deliverability problem. Most issues come down to domain setup, list hygiene, and engagement. The good news? Every one of these can be fixed with the right habits and consistent monitoring.
Authenticate your domain, keep your contact lists clean, send content people actually want to read, and build engagement over time. HubSpot gives you the tools — it’s how you use them that determines inbox success.