Hit The Inbox Again

Send your email :

Inboxbooster detects and fixes email in spam for over 2,000 companies


We built Inboxbooster on the idea that if we help users understand why they’re in spam, they can fix their emails, and stay in inbox.

  • Content Analyzer detects words triggering spam placement
  • Reputation Checker does your domain sends you to spam or promotion
  • Header analyzer we analyze all of your header for compliance
  • DNS deliverability checks SPF, DKIM, DMARC
  • Inbox Placement Test knows with confidence if you are in spam or promotion

How Inboxbooster works?

Inboxbooster queries spam filters to understand what is wrong with your emails.

With one of our users, spam placement was caused by an URL. In another case, our customer had a low domain reputation. We managed to send his email to the inbox, and he carefully removed the less engaging email to fix the root cause problem.

How Inboxbooster helps?

We built Inboxbooster on the idea that if we help users understand why they’re in spam, they can fix their emails. Our job is to make your email goes to the inbox.

  1. With our inbox placement test, we confirm the issue.
  2. We analyze your delivery infrastructure and offer the solution.
  3. We evaluate the reputation of your domain and your sending IP. If it’s low, we’ll give you a way to fix it.
  4. We analyze the content of your emails (from, body, etc.). The precision is about 12 characters (100 bytes). We will flag all the parts of your emails triggering the spam filter.

Because deliverability issues are caused by a combination of factors, our resolution process is iterative. Once you’re deployed the first fixes, we’ll re-run the test. If the issue is not fixed, we’ll give you the next steps.

Our Deliverability Blog

  • Deliverability Monitoring

    If you ever wondered “are my emails in spam” this tool is for you. Inboxbooster is a free tool to tell you when your mails are in spam. When we detect an email going to spam on Gmail, we will email you to warn you. This is a surprisingly complicated subject because Google spam filter…

About Us

We have over 2,000 happy users, including YCombinatorZengo, and Wizbii.

Nicolas and Marcus built this product. We are a proud two-people company. Nicolas is a deliverability expert. He co-founded an email delivery company and delivered more than 50 billion emails. Marcus is a recognized CTO who co-founded Pond5.

CREATED BY MANYCORE.IO | Terms of Service | Privacy Policy | CCPA