Top 5 Inbox Placement Tools to Reduce Spam Rate in 2025

For B2B start-ups, small businesses, and large enterprises, cold outreach is one of the fastest ways to generate leads and sales meetings. However, reaching prospects consistently is difficult when emails end up in spam folders, or when providers like Google and Microsoft suspend mailboxes for poor sending practices.

Inbox placement tools help marketers see exactly where emails land, primary inbox, spam, or promotions, and provide insights to improve delivery. The 2023 benchmark shows nearly 1 in 6 marketing emails never reach the inbox, which means lost engagement and revenue. Emails hitting the primary inbox have much higher chances of being opened, making inbox placement monitoring essential for campaign success

An email may be technically “delivered” but still filtered into a spam folder, which drastically reduces deliverability.

Inbox placement tools address this with features such as:

• Inbox placement testing: Simulates delivery across major providers to diagnose filtering issues
• Email warmup: Builds sender reputation by gradually scaling volume and mimicking natural engagement signals

With a plethora of inbox placement tools in the market, identifying which features matter can help businesses choose the right platform.

7 Must-Have Features in Inbox Placement Tools

Email inbox placement tools should provide clear and realistic ways to improve email delivery and engagement.

Not every tool that claims to improve email deliverability focuses on inbox placement. For instance, list validators like Bouncify clean your email lists but do not provide email placement data or sender reputation warmup.

So, the following features are essential when selecting an inbox placement tool, as they impact campaign success and sender health:

Multi-provider email testing

Look for tools that deliver to real inboxes across popular services like Gmail and Outlook. This ensures accurate data on email placement, whether messages go to the primary inbox, promotions, or spam. Understanding provider-specific behavior helps adjust campaigns to improve actual delivery.

Sender reputation management through email warmup

The tool should include warmup capabilities that build trust progressively. This involves sending increasing volumes of emails coupled with simulated interactions such as opens, replies, and clicks. The makeup of the warmup network is equally vital; networks with authentic Google Workspace and Microsoft inboxes produce higher sender confidence compared to those relying on generic SMTP servers.

Content review and spam scoring

Effective inbox placement tools check email content for problematic elements such as spam keywords, broken links, or suspicious formatting. They should flag these issues prior to sending to prevent triggers of spam filters.

Authentication checks

Correct SPF, DKIM, and DMARC configuration is essential for sender verification. Tools must perform these checks and walk users through fixing errors to maintain domain trustworthiness.

Advanced analytics through AI

Some tools apply AI and machine learning to detect hidden challenges in deliverability patterns, providing precise recommendations to optimize inbox placement over time.

Smooth CRM and ESP integration

Connecting directly with customer relationship management and email platforms allows teams to automate workflows, align campaigns, and quickly address deliverability problems without manual overhead.

Quick Overview of Top 5 Inbox Placement Tools

This table provides a snapshot of five leading inbox placement tools in 2025, summarizing features, pricing, and best use cases to help select the right fit.

These tools approach inbox placement differently, with varied mixes of testing, warmup, diagnostics, and integrations. Let’s look at each tool one by one.

MailReach

‍MailReach is exclusively designed for B2B cold outreach sales teams, lead-generation agencies, and businesses serious about scaling multiple inboxes and managing deliverability. Its focus is on delivering a reliable, high-value solution driven by human-like email interactions and backed by a high trust warmup network.

Key features

Focused on real results

‍MailReach offers features that matter, avoiding cosmetic features that don’t impact deliverability. Scott Robertson, one of MailReach’s users, shared that among all the providers they’ve tried, MailReach has been one of the best. From easy mailbox setup to clear and detailed analytics, the experience has been consistently positive. He added that since using MailReach, their team has seen noticeable improvements in email delivery performance, calling it an excellent mail warming service.

Quality warmup network

‍MailReach’s speciality is its email warmup network, powered by over 30,000 genuine Google Workspace and Microsoft 365 inboxes. This user network beats generic SMTP servers, directly impacting inbox placement with Gmail and Outlook, key providers for B2B cold email success.

Accurate inbox placement monitoring

‍Real-time tracking shows where emails land across Gmail, Outlook, Yahoo, and Zoho. This clarity helps pinpoint delivery problems early and adjust campaigns accordingly.

Reliable spam testing

‍MailReach’s Email Spam Test provides a clear, unbiased reputation score and checks key factors affecting deliverability, including SPF, DKIM, and DMARC records, blacklist status, link security, HTML structure, and spam keywords. This helps you quickly identify and fix issues that block your messages from reaching the inbox.

Built for scale and control

‍Large organizations can manage reputation scores by domain, use tags for mailbox organization, receive alerts on reputation drops, and automate workflows through warmup API.

Natural, human-like engagement

‍Instead of repetitive, robotic patterns, MailReach’s warmup mimics real email behavior. Subject lines vary, replies and stars occur organically, and emails move out of spam folders naturally. This subtlety minimizes suspension risks and keeps mailbox health intact.

Andrew N, Co-founder and CMO at Kulea.ma manages warmup campaigns for multiple clients and evaluated many tools before selecting MailReach. He chose MailReach because its bots simulate real human email behavior by carrying out multiple layers of conversations, rather than sending just one email like many other platforms. This approach helps build a stronger sender reputation and improves inbox placement, reducing the risk of emails in spam. 

Best for

SMEs and enterprise businesses with large outbound sales teams or outreach campaign

Pros

• Effective warmup network with Gmail and Microsoft inboxes (Capterra)
• Natural warmup that reduces spam risks (G2)
• Strong spam filtering and placement tests (G2)
• Tools for large-scale mailbox management (Capterra)
• Highly rated, responsive customer support (G2)

Cons 

• Designed for B2B senders, not for B2C campaigns. For teams managing many inboxes, costs can escalate slightly with the per-inbox model (G2)
• MailReach specializes in warmup and deliverability diagnostics and does not handle campaign sending, reply management, or automation workflows. Users must integrate it with other tools for complete outreach

Pricing

Folderly

Folderly is an all-in-one email deliverability tool combining AI-powered diagnostics with expert consulting. It helps businesses identify hidden inbox placement issues, recover sender reputations, and optimize email health. 

With features like automated warmup, detailed analytics, and CRM integration, Folderly supports high-volume and complex campaigns needing full deliverability management.

Key features

AI-powered deliverability diagnostics

‍Folderly uses advanced AI algorithms to analyze your sending patterns, domain health, and email content. It detects hidden deliverability issues, spam triggers, and engagement problems before they impact your campaigns.

Automated and managed basic warmup service

‍The warmup process is both automated and guided by expert oversight. This approach lets you steadily increase sending volumes while simulating authentic recipient interactions to rebuild or establish sender reputation without triggering spam filters.

In-depth deliverability dashboard

‍Folderly provides a centralized dashboard showing inbox placement rates, spam triggers, blacklist monitoring, sender score, domain health, SPF/DKIM/DMARC compliance status, and more. This gives users a complete view of their email delivery status and actionable recommendations.

Real-time alerts and issue resolution

‍Get instant notifications if your emails land in spam or if there are sudden drops in reputation. Folderly provides guidance on fixing these issues promptly to prevent major campaign disruptions.

Deliverability consulting and support

‍Along with automated tools, Folderly offers bespoke consulting services to help you diagnose complex problems and implement best practices, providing both technology and human insight for optimal deliverability.

Best for

Folderly is best for enterprises, agencies, and marketing teams that require advanced deliverability management with expert guidance. It excels in improving inbox placement, monitoring sender reputation, and resolving complex email delivery issues.

Pros

• AI-powered diagnostics combined with expert guidance catch hard-to-detect deliverability issues (Capterra)
• Basic warmup feature rebuilds sender reputation under expert oversight (G2)
• Dashboard is intuitive, presenting complex data clearly and enabling swift corrective actions (G2)
• Customer support is responsive and helpful, especially for enterprise clients (G2)

Cons

• Pricing is high compared to basic tools (Capterra)
• Platform complexity and consultancy services require thoughtful onboarding and training (Capterra)
• Folderly’s SPF reports are inconsistent, sometimes showing “pass” and “fail” for the same record, which casts doubt on their data accuracy (G2)
• Includes cosmetic warmup features like template, industry, and language warmup that deliverability experts often view as unnecessary or ineffective

Pricing

Folderly’s pricing starts at $96 per mailbox per month for 1-9 mailboxes; for more details on custom pricing, visit the pricing page

Lemwarm

Lemwarm is an email warmup tool created by the Lemlist team to help small and medium businesses and sales teams improve sender reputation and email deliverability. It automates the warmup process using a network of email accounts, ensuring outreach emails avoid spam filters and reach recipients’ primary inboxes more reliably.

Key features

Peer-to-peer warmup network

‍Lemwarm connects your email account with a network of over 10,000 real users, exchanging warmup emails to build authentic engagement and strengthen trust with email service providers (ESP).

Industry-specific clusters and human-like interaction

The tool groups users into Smart Clusters based on industry and sending behaviors, sending personalized warmup emails that mimic actual conversations, including scrolling and clicking links to signal genuine interactions.

Customizable warmup schedules and templates

‍Users can customize warmup timing and personalize email templates, especially on premium plans, providing control over how the warmup adapts to their specific outreach patterns.

Deliverability monitoring dashboard

‍Lemwarm offers a clear dashboard showing inbox vs. spam placement, sender reputation score, blacklist status, and authentication checks, keeping users informed of their email health in real time.

Technical setup checker

‍Built-in checks for SPF, DKIM, DMARC, and MX record configurations make sure foundational email authentication is in place for successful warmup and outreach.

Integration with major providers

‍Works well with common email services and fits within the Lemlist ecosystem, while also supporting other email infrastructures through standard protocols.

Best for

Lemwarm works well for small to medium businesses and sales teams seeking an easy-to-use, automated email warmup solution. It’s particularly useful for those already using Lemlist or looking for peer-to-peer warmup within a real-user network.

Pros

• Peer-to-peer warmup network of email users ensures authentic engagement and improves deliverability (Capterra)
• Smooth integration if you’re already using Lemlist for outreach (Capterra)
• Set-it-and-forget-it operation that requires minimal manual setup
• UI is clean and beginner-friendly

Cons

• Cosmetic warmup logic: template or industry-based engagement doesn’t influence ESP reputation and can create detectable automation patterns
• No verified inbox network: signals are generated within Lemlist’s internal user base, which limits credibility with Gmail and Outlook
• Limited to 40 warming emails/day on entry plans

Pricing

GlockApps

GlockApps is an inbox placement and email deliverability testing platform built for individual users, small businesses, and agencies. It helps marketers and senders analyze where their emails land, detect spam triggers, monitor DMARC compliance, and track sender reputation to maximize deliverability.

Key features

Inbox placement testing

‍Lets you test where your emails land across major providers like Gmail, Outlook, Yahoo, Apple, and others. It shows if emails reach the primary inbox, spam folder, or promotional tabs, helping you understand actual deliverability.

Spam filter diagnostics

‍The tool analyzes your email content, links, images, and HTML for elements that trigger spam filters. It identifies content issues that could harm your inbox placement.

Seed list testing

‍GlockApps provides extensive seed lists (over 100+ email addresses) representing major ISPs worldwide. You send your test emails to these addresses, enabling an accurate inbox placement and spam score report.

Automated and manual tests

‍Supports scheduled automated tests and manual testing for flexible deliverability checking. Automated tests can alert you when certain deliverability thresholds drop, ensuring proactive monitoring.

Email authentication analytics

‍Process DMARC reports showing domain usage and authentication status including SPF, DKIM, DMARC. This helps detect spoofing and tighten email security.

Best for

GlockApps is best for email marketers, IT teams, and agencies needing accurate inbox placement testing and spam diagnostics without warmup features. It fits well for those who want to monitor domain and IP reputation and improve deliverability through ongoing testing and technical insights.

Pros

• Provides precise inbox placement testing across major email providers, helping users identify where their emails land (Primary inbox, Spam, Promotions, etc.) (Capterra)

• Strong API support enables integration into existing workflows and tools (Capterra)

• Tracks domain and IP reputation including blacklist status, helping maintain a healthy sending environment (Capterra)

Cons

• Lacks built-in email warmup features, focusing solely on testing and diagnostics

• Managing very specific use cases like double opt-in confirmation emails may require custom workaround due to testing list constraints (Capterra)

Pricing

Gmass

Gmass is an email deliverability tool specifically focused on spam and promotion folder testing within Gmail. It is engineered primarily for teams using Google Workspace who run cold outreach campaigns and want to optimize their Gmail placement. Its standout capability is precise detection of whether emails land in Gmail’s spam or promotions folders, combined with campaign automation features tailored to the Gmail ecosystem.

Key features

Gmail spam and promotions folder testing

‍Precisely tests if your emails land in Gmail’s Inbox, Spam, or Promotions tabs, delivering Gmail-specific deliverability insights.

Spam solver tool

‍An AI-powered spam checker that analyzes your emails, suggests tweaks, and allows retesting to improve inbox placement.

Campaign automation & mail merge

‍Easily integrates with Google Sheets for personalized mail merges, scheduling, auto follow-ups, and A/B testing within Gmail.

Custom tracking domain

‍Enables use of branded tracking domains instead of defaults to improve sender reputation and reduce spam flagging.

Best for

Gmass fits individuals and small teams using Gmail or Google Workspace. It excels at sending cold outreach and personalized campaigns with easy Gmail integration and automation.

Pros

• Affordable and easy-to-use with smooth integration into Gmail/Google Workspace for quick setup (G2)
• Accurate Gmail-specific spam and promotions folder testing improves cold outreach targeting
• Campaign automation featuring mail merge, scheduling, auto follow-ups, and A/B testing (Capterra)

Cons

• Limited strictly to Gmail; no support for Microsoft or other ESPs (Capterra)
• Users report occasional false open tracking and cluttered sent folder due to Gmail integration (Capterra)
• Lacks built-in warmup capabilities, requiring third-party tools for sender reputation building

Pricing

They also offer various team and enterprise plans to accommodate larger organizations with multi-user collaboration and advanced features.

Important Considerations When Choosing Inbox Placement Tools

Gradual warming using email warmup tools

Good email warmup tools build sender reputation step-by-step by gradually increasing sending volumes and mimicking natural recipient interactions like opens, clicks, and replies. This gradual approach prevents spam flags and boosts inbox trustworthiness over time.

Verification and testing using spam testers

Continuous email verification and spam testing tools analyze email content and delivery to detect spam triggers and poor inbox placement early. This ensures campaigns avoid filter traps and reach the highest-visibility folders, improving engagement rates.

Composition of the warmup network

A critical factor highlighted by deliverability experts is the quality of the warmup network. Warmup tools using real Google Workspace and Microsoft 365 inboxes produce stronger sender reputations and better inbox placements compared to platforms relying on generic SMTP or junk inboxes. The network makeup ultimately determines warmup effectiveness and inbox success.

Pricing structures 

Transparent and scalable pricing models help businesses evaluate tools risk-free. Consider per-inbox or per-user pricing, volume discounts, and whether essential features are gated behind premium plans.

Why Should You Choose MailReach?

MailReach stands out as a forward-thinking solution that helps marketers automate warmup and optimize inbox placement, making sure campaigns reach their full potential. It also provides tools to monitor and improve sender reputation through a unique reputation score, perform spam tests to check email content safety, and provides access to a large warmup network for meaningful engagement.

Key features include:

• Automated email warmup for steady sender reputation growth
• Real-time inbox placement monitoring across major providers
• Spam content testing to identify risky words, broken links, and formatting errors
• A unique reputation score to track and manage sender health
• Access to a warmup network of over 30,000 genuine inboxes
• Responsive, expert customer support to resolve deliverability issues quickly

Don’t Miss Another Open

Deliverability will only become more critical in 2026. The inbox placement tools you choose today determine whether your emails reach audiences or get lost in spam. Focus on platforms that deliver tested inbox placement insights, warmup your sender reputation authentically, and provide actionable diagnostics.

Check your spam score and inbox placement with MailReach now.