February 21, 2023

5 Leading Inbox Placement Tools of 2023 (Features & Pricing)

Explore the top five inbox placement tools of 2023 along with their key features and pricing.

5 Leading Inbox Placement Tools of 2023 (Features & Pricing)

An inbox placement tool can increase your email response rate by keeping emails out of the spam folder and ensuring they land in the primary inbox. This is the area of the inbox where prospects and customers are most likely to read messages every day. 

In this article, we'll discover what an inbox placement tool is, explore five popular tools, and discuss the key features your inbox placement tool should ideally have.   

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What Is an Inbox Placement Tool? 

An inbox placement tool is for businesses and marketing/sales teams who want to uncover and optimize the percentage of the emails they send which are landing in the primary inbox rather than other locations which rarely get opened (such as folders for spam emails, junk folders or unfocused folders)

This technology can be beneficial for any outbound email campaign and follow-up, as these emails are more likely to hit the spam folder than opt-in communications (like email marketing campaigns to subscribers).

The email tool should ideally pinpoint any inbox deliverability issues and outline steps for enhancing your email performance.

Tip: If you'd like a detailed overview of what features a good inbox placement tool should include, click here to jump to that section. You can then scroll back to our list of the top 5 inbox placement tools.

With that said, let's look at some of the top inbox placement tools to address your deliverability needs in 2023:

5 Leading Inbox Placement Tools 

Here are the top five inbox placement and deliverability services you can try today:

1. Allegrow

With billions of emails sent out every day, Allegrow's email deliverability features help you reduce your rate of spam emails, optimize your sender reputation and enhance your inbox placement rate.

The Allegrow platform is based on a premium network of real B2B email addresses. These allow you to measure the percentage of your email traffic reaching the primary inbox each day on a domain-wide or rep-specific basis.

This helps you optimize and build sender reputation across your teams conducting outbound sales. As a result, you can deliver cold email campaigns directly to recipients' primary inboxes and create a scalable go-to-market motion.

Best For:

Larger/Scaling Outbound Business Development Teams.


  • Allegrow has community accounts that monitor where your emails end up to ensure your outbound process is running smoothly and constantly optimize it for a high inbox placement rate.
  • Allegrow works seamlessly alongside your Sales Engagement Platform and existing tech stack (including; SalesLoft,, Salesforce, HubSpot or Close CRM).
  • B2B inboxes inside the Allegrow network provide complex interactions to improve sender reputation. This includes emails being; marked as important, starred, moved out of spam and replied to. 
  • DKIM, SPF and DMARC report monitoring and testing using real email traffic every hour. This means if any of your subdomains/domains have authentication issues that can damage deliverability – Allegrow will notify your team within hours (not days).
  • You can track your spam score and changes to your domain reputation within Allegrow — giving you one source of truth for sender reputation data. 
  • Monitor spam emails and sender reputation for multiple inboxes (email accounts) simultaneously to rank and score your individual SDR team members. The leaderboard functionality helps you identify users whose cold email outreach needs optimization. 

  • Allegrow connects with Google, Office365, and Exchange email accounts.

  • You can A/B test your email content to determine the version least likely to land in spam. This provides unique insight into how spam filters for content specific to your industry and value proposition work in real-time.

  • Provides inbox insight (based on data from thousands of active spam folders) into how you can improve your cold email performance - around metrics like email content size, sending patterns and sequence structure.

  • Displays a day-to-day record and forecast of your email-sending patterns (on a per-rep basis).


($36/user per month): 
This package lets you track your spam rate and sender reputation.

  • Track sender reputation on the dashboard.
  • Monitor spam rate changes.
  • Chat & Email support.

Premium ($72/user per month): 
This package helps you track and raise your sender reputation if you send less than 20,000 emails monthly.

  • All Tester features.
  • Positive interactions to boost sender reputation.

Scale Plus (POA):
The package to track and increase your sender reputation if you send more than 20,000 emails per month.

  • All Premium features.
  • Multiple domains/subdomains connected.
  • Email Testing & Optimization.
  • Over 25+ users' emails connected.

Check out our article to understand how you can boost your inbox placement rates.

2. Validity (Everest) - Previously Return Path

Validity's Everest is an email deliverability platform that primarily focuses on tracking and reporting existing metrics from your newsletter or marketing automation software. 

Best For:

B2C email marketing teams - analyzing data sending to an extensive opt-in email list of subscribers.


  • Inbox placement metrics (from 3rd party data, NOT actual B2B inboxes).
  • Diagnose and prioritize problem areas in your emails.
  • Compare your performance metrics with other sender benchmarks.
  • Exclusive Sender Reputation Certificate program.


  • Elements: $20/month, 5,000 emails/month
  • Elements Plus: $525/month, 20,000 emails/month
  • Professional: Custom pricing
  • Enterprise: Custom pricing

3. Litmus

Litmus is an email marketing platform focused on helping email managers and designers test their HTML content to enhance email deliverability and engagement.

Best For:

Email design teams that send HTML-based email content to an opt-in email list of subscribers. 


  • Preview any email campaign in popular email clients.
  • Comprehensive and automated QA tests.
  • Inbox placement tests (From Seed lists, NOT real B2B inboxes)
  • Test email with easy integrations (to platforms like Mailchimp, Klaviyo and Campaign Monitor)


  • Litmus Basic: $99/month, one user
  • Litmus Plus: $199/month, 5 users
  • Litmus Enterprise: Custom pricing

4. Kickbox

Kickbox is an inbox placement solution that permits you to see where your emails land within the inbox.

Best For:

B2C email marketers who want to run inbox placement tests. 


  • Inbox Placement Tests (From a seed email list, NOT actual B2B inboxes)
  • Blocklist Monitoring (which is less relevant for B2B sales teams that send through Google Workspace or Outlook accounts – but helpful for senders using 3rd party SMTPs)
  • Reputation Monitoring
  • Precheck


  • Starter: $250/month
  • Plus: $500/month

5. Glock Apps

The Glock Apps platform provides several deliverability tools to diagnose your inbox placement rate issues using manual tests users run and send to Glock Apps seed accounts.

Best For:

SMB B2B email marketers sending less than 5,000 emails per month - who want to run manual tests and utilize ad-hoc professional services for DMARC, SPF and DKIM set-up


  • Email spam tests.
  • Sender authentication check.
  • Reputation check for all sending IPs.
  • Spam filter score check.
  • Access to email testing via proxy email addresses. (This means Glock Apps Seed lists, NOT real B2B inboxes)


  • Personal: Free plan
  • Basic: $59/month
  • Business: $99/month
  • Custom: $149/month

Free Bonus Tool - Google Postmaster Tools 

 Postmaster Tools by Google can provide insight into the sentiment of G Suite users towards your email traffic. As a free option, most users will use this in addition to an inbox placement tool. 

Best For:

Monitoring spikes in manual spam reports from Gmail or G Suite users, which can help give insight if one of your campaigns/audiences has bad sentiment. 



  • Free - data specific to Google users, which only gives an indication of manual spam reports not where your emails land on average.

5 Key Features Your Inbox Placement Tool Should Have

These are some of the critical features you'll want to be aware of when you're comparing different deliverability tools:

1. Spam Rate Monitoring

There are two different types of spam rates to be aware of and track:

a)  The spam complaints rate on your emails. (This can lead to a worse sender reputation and email account suspensions).

b) The rate at which your emails automatically land in the spam folder rather than the primary inbox. (This is the silent killer of outreach campaign engagement).

The spam complaints rate or spam rate is the percentage of recipients reporting your email as spam out of the total number of sent messages. 

For example, if you send 2,000 emails and 2 people label it spam, your spam rate will be 0.1%. 

Recipients would likely report an email as spam when the outreach has annoyed them:

The industry-acceptable spam rate is 0.1% or less; anything above this threshold could undermine your email deliverability. 

Consequently, you'll even find that even Google Workspace or Outlook accounts are suspended by your email service provider when this happens too often. The easiest way to access this data for free is from Google Postmaster Tools

However, the reported rate will not show if your emails automatically land in spam folders.

One important point to note when monitoring spam rates is that most emails landing in spam end up there automatically rather than being moved there due to a report. 

Therefore, you'll want to ensure you can accurately monitor the average percentage of your email traffic automatically landing in the spam folder. 

Being able to track the spam rate of the specific content you use in the go-to-market process is vital to hitting the primary inbox sustainably over the long term. 

Learn more about why you should monitor your inbox placement rates.

2. A Network of Real Mailboxes 

To get real, first-party data on inbox placement - any viable technology solution on the market needs: 

  • The ability to access inboxes 
  • See where your emails land inside these mailboxes
  • Report the data back to you

Therefore, the general approach to sourcing this data can be summarized in 3 steps: 

  1. Emails will be sent from your domain/email account(s) to other external inboxes
  1. The monitoring solution can access your mailbox provider data and log which folders they landed in. (inbox,  spam, social, updates, promotions, unfocused, junk).
  1. The monitoring solution uses the data from your email service provider on what percentage of the overall 'sent emails' landed in the primary inbox to calculate the sender reputation and report this back.  

To separate the good from the bad in the market, you'll want to consider which vendor provides the highest quality data for your use case. 

The main aspects to consider when assessing data quality can be split into two categories:

A. The Seed / Real Inboxes Used in the Network

Most platforms use email accounts set up or purchased in bulk by the monitoring provider. 

The issue with this process is that although your emails won't run into a spam trap, the email addresses in the network are not unique domains or representative of real business inboxes (any email provider knows when an account is fake). 

Therefore, the data you receive on inbox placement from networks made from these inboxes is inaccurate. They won't show the variation in sender reputation, which marketers rely on to make decisions. 

Allegrow automatically conducts inbox placement tests every hour using real email traffic and reaches out to admins to notify them of every deliverability issue. No other inbox placement provider offers this feature. 

This is vital for any outbound email campaign since your cold email can easily land in spam without frequent inbox placement testing.

Networks like Allegrow are built from unique B2B inboxes (meaning other Allegrow users' real inboxes). Therefore, we're able to provide data that is representative of a real B2B prospecting audience. 

On the other hand, if your ICP is a consumer, Allegrow's network would be a bad fit as it is created from business domains/users. 

B. The Sample Size and Period to Calculate the Score

Many SMB-focused email testing platforms will either:

  • Use a relatively low sample size (meaning under 100 data points) and run a sender and IP reputation rate calculation from this data or,
  • Send a batch of emails to calculate sender and IP reputation rather than continually sending emails over multiple days/weeks and calculating the average score based on various data points. 

A free solution that works with these sample sizes or single/one-off batches should be okay if you're just starting to run campaigns at a very low volume. 

However, if you're a professional marketer, these sample sizes will not be statistically relevant compared to the number of emails you send. 

Therefore you'll need a platform that uses a larger sample size and consistent monitoring. 

3. Content Testing

Your general sender reputation, as well as your emails, will be specifically filtered based on their content. 

This is one reason why different email subject lines/content can have drastically different results when you look at your engagement statistics. 

Any mailbox provider (like Google and Microsoft) uses AI to compare what you send against other content which has received low engagement in the past (or been marked as spam complaints) to make automatic decisions for filtering emails.

Therefore, avoid practicing content on your prospects as it can lead to lost opportunities. 

Instead, you should use an inbox placement platform that allows you to test how different variations of your outreach content are filtered in actual mailboxes.

4. Reputation Insights and Interactions

A fundamental element for successful inbox placement is good sender reputation.

Sender reputation represents the trustworthiness of the email domain and IP address you use to send your emails. It lets every email service provider know whether you're a spammer or not. 

And how does an email provider gauge the risk potential of your email domain and IP address?

They take multiple factors into account to evaluate your sender reputation, such as:

  • Content quality of your emails.
  • Quality of contacts you send your emails to.
  • Level of engagement among recipients of your messages.
  • Volume patterns and level of sending from your accounts and IP address.

Many inbox placement tools give you a sender reputation score depending on the above metrics. This gives you a real-time indication of how your overall outreach strategy impacts inbox placement.

Good inbox placement tools will also devise ways to improve your reputation actively. 

For instance, a platform like Allegrow makes your email account act like a real human by: 

  • Executing unique email actions every day to boost your reputation
  • Providing inbox insight based on data from thousands of active spam folders

5. SPF, DKIM, and DMARC Report Monitoring

Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting & Conformance (DMARC) are email authentication standards that prevent spammers from sending phishing and spoofing emails through your domain. 

These standards are critical to safeguarding your recipients and your sender reputation:

  • With the SPF protocol in place, your emails pass SPF checks on the recipients' end and are considered more reliable by their servers. With this, you're also more likely to reach the reader's primary inbox instead of ending up in the spam folder. 
  • As for the DKIM protocol, a DKIM signature will be automatically attached to your outgoing emails. This signature lets the recipient server verify your email's authenticity and ensure that it hasn't been tampered with in transit.
  • The DMARC report protocol combines the SPF and DKIM signals to deter phishing attacks. It also guides the recipient email server on what to do with messages that fail email verification – reject or quarantine them.

Once you connect your email account with an inbox placement tool like Allegrow, it runs comprehensive SPF, DKIM, and DMARC tests on every outreach email account and domain you send from. 

If your email(s) fail the authentication test, the email deliverability tool will inform you immediately. This plays a significant role in safeguarding your sender reputation, as you can take preventive measures before damage is done. 

Jump back to the list of tools.

Level Up Your Inbox Placement Strategy with Allegrow

With the right inbox placement tool, you'll be able to master the science of hitting the right inbox folders and have an advantage over your competitors. 

While many of these deliverability tools have something to offer, Allegrow is a comprehensive inbox placement tool built for B2B business development teams. 

It provides the accurate data and actionable inbox insights combined to improve sender reputation. 

Sign up with Allegrow today to amp up your inbox placement efforts and boost deliverability.