Email Deliverability Testing

Run an Email Deliverability Test Before You Hit Send

See exactly where your emails land at Gmail, Microsoft O365, Hotmail, Yahoo, Apple Mail, and Zoho. Catch spam folder issues before your subscribers never see your message.

Starting at $19.99/mo — unlimited inbox placement tests

Start Testing Today → See How It Works

Test inbox placement across all major email providers

Gmail
Microsoft O365
Hotmail
Yahoo Mail
Apple Mail
Zoho Mail

Inbox or Spam?
Know Before You Send.

Our email delivery test sends your message to real seed addresses across every major ISP. Within minutes, you'll see exactly where each email landed — primary inbox, spam folder, or promotions tab.

Run Your First Test →
// email delivery test — 70 seed addresses
Gmail ✓ 14/15 Inbox
93%
Microsoft O365 ✓ 12/14 Inbox
86%
Hotmail ⚠ 5/12 Inbox
42%
Yahoo ✓ 10/12 Inbox
83%
Apple Mail ✕ 2/9 Inbox
22%
Zoho ✓ 7/8 Inbox
88%
→ 50/70 seeds reached the inbox (71%) → See anything alarming? Schedule an email deliverability consultation
See It In Action

Watch How the Inbox Placement Tester Works

A quick walkthrough of how to run an email deliverability test, read your results, and take action.

How It Works

Three Steps to Test Your Email Deliverability

No code. No complicated setup. Send an email, get real placement data from real inboxes.

1

Get Your Seed Addresses

We provide over 70 unique seed email addresses spread across Gmail, Microsoft O365, Hotmail, Yahoo, Apple Mail, and Zoho — with multiple seeds per provider to reveal how ISPs inconsistently filter the same email.

2

Send Your Email

Send each seed address a separate email exactly as you would in a real campaign. Use your actual ESP, real sending domain, and live content. Don't CC or BCC multiple seeds.

3

Get Your Deliverability Report

See where each email landed — inbox, spam, or promotions tab. Review header analysis, SCL scores, ICL data, and get actionable recommendations. Export as CSV or PDF.

Features

Everything You Need to Diagnose
Email Deliverability Issues

More than a simple spam score. Real inbox placement data from real mailboxes at every major provider.

70+ Seed Inbox Placement Testing

Test across 70+ seed addresses at Gmail, Yahoo, Hotmail, Microsoft O365, Apple Mail, and Zoho. ISPs filter inconsistently — testing many seeds per provider reveals the true distribution of your inbox placement.

Email Header Analysis

Examine full email headers including Microsoft's Spam Confidence Level (SCL), Apple's Inbox Confidence Level (ICL), and authentication results for SPF, DKIM, and DMARC.

Content Optimization with Campaign Cleaner

Upload your email for analysis and fine-tune content to improve inbox placement. Fix spam triggers, optimize text-to-image ratios, and clean up HTML issues.

Downloadable Test Reports

Export complete inbox placement results as CSV or PDF. Share deliverability data with your team, track performance over time, and build a historical improvement record.

ISP-Specific Metrics

Understand How Each Provider
Scores Your Email

Every major ISP uses different signals to decide inbox vs. spam. Our test shows you where your email landed and what's in the headers — but to get the full picture of your domain's reputation, you'll want to check each provider's postmaster tools directly.

Gmail — Google Postmaster Tools

Our test tells you if your email hit the inbox or spam at Gmail. To understand why, create a free account on Google Postmaster Tools. Google will give you a complete breakdown of your domain reputation (Bad to High), IP reputation, spam rates, and authentication pass/fail — data only Google can provide.

DOMAIN + IP REP

Microsoft O365

Hotmail and O365 share Microsoft's infrastructure but maintain separate scoring and reputation databases. Our test extracts O365's SCL and BCL scores from the headers independently. An email can land in the inbox at O365 but hit junk at Hotmail — which is why we test both separately. For deeper IP reputation data, check Microsoft SNDS.

SCL + BCL IN HEADERS

Hotmail

Hotmail and O365 share Microsoft's infrastructure but maintain separate scoring and reputation databases. Our test extracts Hotmail's SCL and BCL scores from the headers independently. An email can land in the inbox at O365 but hit junk at Hotmail — which is why we test both separately.

SCL + BCL IN HEADERS

Apple Mail (iCloud)

Apple uses an ICL (Inbox Confidence Level) score based on engagement, authentication, and delivery history. We report where your email landed at Apple Mail and surface any ICL data available in the headers. Apple does not offer a public postmaster dashboard.

ICL SCORING

Yahoo Mail — Sender Hub

Our test shows inbox vs. spam placement and header details at Yahoo. For deeper insight into complaint rates and delivery performance, sign up for Yahoo Sender Hub — Yahoo's postmaster platform with CFL data, spam complaint rates, and domain-level delivery statistics.

CFL + SENDER HUB

Zoho Mail

Zoho applies strict authentication-based filtering with its own spam detection. Our test shows placement and header data at Zoho. This is especially important for B2B senders whose recipients use Zoho Workplace — a provider often overlooked by other inbox placement tools.

AUTH + FILTERING
Deliverability Guide

Why Do Emails Land in Spam?

Hundreds of factors influence email deliverability. Here are the most common culprits — and what to do about them.

How to Fix Spam Placement

  • Set up SPF, DKIM, and DMARC authentication properly on your sending domain
  • Only send to opted-in, engaged subscribers — not purchased or scraped lists
  • Remove unsubscribes and feedback loop complaints immediately
  • Warm up new domains and IPs gradually before sending at volume
  • Monitor sending patterns — avoid sudden spikes in email volume
  • Encourage replies and engagement to train ISP filters in your favor
  • Use Campaign Cleaner to optimize content and eliminate spam triggers
  • Run inbox placement tests before every major campaign
Optimize Your Emails →

The Complete Guide to Email Deliverability Testing

Email deliverability refers to whether your message actually arrives in a recipient's inbox — not just whether the server accepted it. You can have a 99% delivery rate and still suffer from terrible deliverability if most of your emails are landing in spam folders or promotions tabs where subscribers never see them.

That's why running an email delivery test is critical before every major campaign. An inbox placement test sends your email to real seed addresses at providers like Gmail, Microsoft O365, Hotmail, Yahoo, Apple Mail, and Zoho, then reports back exactly where each message landed. This is fundamentally different from a spam score checker, which only analyzes your content for red flags. Real-world placement data tells you what's actually happening.

Why ISPs Filter Emails Inconsistently

A common misconception is that spam filtering is binary — your email either goes to the inbox or it doesn't. In reality, ISPs distribute emails inconsistently. The same email sent to the same provider might reach the inbox for 30% of recipients and land in spam for the remaining 70%. This distribution depends on individual engagement history, sender reputation at the IP and domain level, authentication results, and the content itself.

This is why testing with many seed addresses per provider is essential. A single test email to one Gmail address doesn't tell you the full story. Our inbox placement tester uses over 70 seeds across ISPs — including separate seeds for Microsoft O365 and Hotmail, which can filter differently despite sharing Microsoft's infrastructure — to reveal the actual distribution of your deliverability.

Email Delivery vs. Email Deliverability

These terms sound similar but mean very different things. Email delivery means the recipient's mail server accepted your message — it didn't bounce. Email deliverability is about what happens next: did the message reach the primary inbox, get sorted into a secondary tab, or get buried in the spam folder? You need both, but deliverability is what determines whether anyone actually reads your email.

What Factors Affect Email Deliverability?

Email deliverability is influenced by three broad categories. Technical factors include your IP reputation, domain authentication (SPF, DKIM, DMARC), and whether your sending infrastructure is properly warmed up. Sending factors cover your domain and sender reputation, sending patterns, list hygiene, and how recipients have historically engaged with your emails. Content factors include subject line quality, HTML structure, text-to-image ratio, link reputation, and whether your message contains known spam trigger words or phrases.

No single factor determines placement. ISPs use machine learning models that weigh hundreds of signals together. That's why a comprehensive email delivery test — one that checks placement across Gmail, Microsoft O365, Hotmail, Yahoo, Apple Mail, and Zoho, analyzes headers, and evaluates content — gives you the most complete picture of what's happening with your emails.

When to Run an Inbox Placement Test

The best practice is to test before every significant campaign send. Beyond that, you should run an email deliverability test whenever you change ESPs or sending infrastructure, switch to a new sending domain or IP, notice a drop in open rates or engagement, make significant changes to your email template or content, or increase your sending volume substantially. Regular testing catches problems early — before they damage your sender reputation or cost you revenue from undelivered messages.

FAQ

Frequently Asked Questions

An email deliverability test sends your email to seed addresses at major providers like Gmail, Microsoft O365, Hotmail, Yahoo, Apple Mail, and Zoho to check whether it lands in the inbox, spam folder, or promotions tab. It helps you diagnose issues before sending to your real audience.

We provide over 70 seed addresses across major ISPs. You send your email to these addresses (separately — not CC'd together). Our system checks where each email landed: primary inbox, spam folder, or a secondary tab. Results include full header analysis, ISP-specific scores like Microsoft's SCL and Apple's ICL, and actionable recommendations.

Emails land in spam due to poor IP or domain reputation, missing authentication (SPF, DKIM, DMARC), spammy content triggers, low engagement rates, blacklist listings, or sudden spikes in sending volume. An inbox placement test helps pinpoint the exact cause so you can fix it systematically.

Our inbox placement test covers Gmail, Microsoft O365, Hotmail, Yahoo Mail, Apple Mail (iCloud), and Zoho Mail, with over 70 seed addresses spread across providers. We're continuously expanding coverage and adding new seeds.

Inbox placement testing starts at $19.99 per month. This gives you access to the full Inbox Placement Test Center with 70+ seed addresses across all supported providers, email header analysis, downloadable CSV and PDF reports, and content optimization through Campaign Cleaner. Need hands-on help? You can also schedule an email deliverability consultation with our team.

A spam score checker analyzes your email content for red flags. An inbox placement test actually sends your email to real seed inboxes and reports where it lands. Our tool provides real-world placement data plus content analysis — giving you the complete picture.

Email delivery means the recipient's mail server accepted your email — it didn't bounce. Email deliverability is whether your email reached the inbox or got filtered into spam. You can have 100% delivery but terrible deliverability if every email goes to junk. Our test measures actual deliverability.

Yes. Download your complete inbox placement test results as a CSV or PDF report. Share data with your team, track deliverability over time, and keep records of your improvements.

Email Delivery Test is powered by Campaign Cleaner. When you click "Get Started," you'll be taken to Campaign Cleaner's registration page to create your account and select the inbox testing subscription at $19.99/mo. Once registered, you'll have immediate access to the Inbox Placement Test Center.

Stop Guessing. Start Testing
Your Email Deliverability.

Find out exactly where your emails land at Gmail, Microsoft O365, Hotmail, Yahoo, Apple Mail, and Zoho — before your subscribers don't see them.

Starting at $19.99/mo

Start Testing Today →