7 Best GlockApps Alternatives — 2026

While GlockApps has served as a go-to inbox placement testing tool for years, e-commerce brands increasingly need solutions that go beyond diagnostics to actually fix deliverability issues. From Mailmend's algorithmic approach that moves emails from Promotions to Primary inbox, to budget-friendly warmup tools like MailReach, these seven alternatives address different aspects of email deliverability for Klaviyo-powered brands and beyond. This comprehensive analysis examines each platform's strengths, pricing models, and ideal use cases to help e-commerce marketers make informed decisions.

Key Takeaways

• Testing vs. fixing trade-off: GlockApps diagnoses deliverability issues but doesn't solve them—Mailmend is the only alternative that actively moves promotional emails from Gmail's Promotions tab to Primary inbox

• Timeline differences matter for e-commerce: Mailmend delivers 24-hour results while warmup tools like Warmy.io require 2-6 weeks, making algorithmic solutions essential for time-sensitive campaigns like Black Friday

• E-commerce brands need specialized solutions: Generic deliverability tools serve B2B cold email use cases, while Mailmend's Klaviyo-exclusive integration addresses the specific challenge of promotional email categorization

• Market expansion signals growing demand: The email deliverability tools market reached $1.2 billion in 2024 and is projected to hit $2.41 billion by 2032, reflecting increased investment in inbox placement solutions

1. Mailmend — Algorithmic Primary Inbox Placement for E-commerce

Mailmend stands as the only platform that directly addresses Gmail's Promotions tab through proprietary algorithmic technology, delivering results within 24 hours rather than weeks.

Key Features:

• Algorithmic code-based inbox placement that bypasses Gmail's promotional categorization

• Native Klaviyo drag-and-drop integration with under 5-minute setup

• Built-in A/B testing within Klaviyo to measure Primary vs. Promotions placement lift

• Zero content changes required—preserves existing email copy and design

• 1-to-1 dedicated client partnerships with hands-on implementation support

• Revenue satisfaction guarantee promising 50-100% email performance improvement

Documented Results:

• Dr. Squatch: 112% email revenue increase, 42% open rate increase and 67% CTR increase within 24 hours

• StickerYou: Day 1 boost of 20% with 100% increase by month 1—64% open rate increase and 43% CTR increase

• Ministry of Supply: Results within one business day—27% open rate increase and 30% CTR increase

• Larsson & Jennings: Saved their Black Friday—82% open rate increase and 51% CTR increase

• Amberjack: "It Actually Worked"—54% open rate increase and 51% CTR increase

• Clevr Blends: Made a big difference—21% open rate increase and 63% CTR increase

Pricing Structure:

• Partnership-based pricing model (requires demo consultation)

• Revenue satisfaction guarantee included

• No per-test or per-inbox fees

• Dedicated implementation support included

The platform serves 500+ e-commerce businesses across personal care, apparel, home goods, food & beverage, and lifestyle categories. For brands preparing for seasonal campaigns or product launches, Mailmend's immediate impact proves invaluable. Explore Mailmend case studies to see documented performance improvements from brands like Sand Cloud and Caraway Home.

2. Warmy.io — AI-Powered Email Warmup Network

Warmy.io leads the email warmup category with sophisticated AI engagement simulation and one of the largest warmup networks in the market.

Core Capabilities:

• 35,000+ businesses using the platform's warmup network

• Advanced AI simulating human behavior patterns (opens, reads, scrolls, clicks, replies)

• Customizable warmup intensity for gradual or aggressive approaches

• Gmail, Outlook, and HubSpot integrations

Pricing Structure: Volume-based pricing in B2B sender, B2C sender, and custom plans; 7-day free trial available

Warmy.io excels for businesses building sender reputation from scratch or managing cold outreach campaigns. However, e-commerce brands with established sender reputation face a different challenge: their emails avoid spam but still land in Promotions. Warmup cannot override Gmail's algorithmic categorization.

3. MailReach — Budget-Friendly Warmup and Testing Combo

MailReach offers the most accessible entry point for email deliverability improvement, combining warmup and testing capabilities at competitive pricing.

Features:

• 30,000+ inbox warmup network for engagement simulation

• Dual functionality combining warmup and inbox placement testing

• Beginner-friendly interface designed for non-technical users

• SMTP universal compatibility

Pricing Structure: Email warmer starts at $20/mailbox per month and 20 free spam test credits per month; Spam test credits start at $28/month for 100 credits.

For small businesses or solopreneurs needing basic deliverability improvement on a budget, MailReach provides solid value. However, the limited testing pool and timeline constraints make it less suitable for e-commerce brands needing rapid, accurate results.

4. Inbox Radar by Saleshandy — Unlimited Testing at Flat Rate

Inbox Radar launched as a cost-effective alternative to GlockApps, offering unlimited inbox placement testing without per-test fees.

Testing Capabilities:

• Coverage across major ESPs

• ESP-to-ESP comparison showing placement breakdown by provider

• Pre-flight check feature simulating how major providers treat messages

Pricing:

• Free: Basic email alerts

• Paid plans at $5/month or $50/year for unlimited circle back emails and advanced email management

Inbox Radar serves agencies and high-volume senders running frequent placement checks. The unlimited testing model eliminates cost anxiety around repeated tests. However, like GlockApps, it diagnoses without fixing—brands still need separate solutions for actual deliverability improvement.

5. Folderly — Premium AI Diagnostics with Consulting

Folderly positions itself in the premium segment with AI-powered diagnostics and included expert consulting for enterprise clients.

Advanced Features:

• AI algorithms detecting hidden deliverability issues traditional testing misses

• Proactive "Spam Fixer" that actively repairs deliverability

• Expert deliverability specialists included in premium tiers

• Centralized dashboard monitoring inbox rates, spam triggers, blacklists, and domain health

Pricing: $96/mailbox/month when billed annually

Folderly appeals to enterprises with dedicated email operations teams and budgets supporting premium pricing. For most e-commerce brands, the cost-to-value ratio doesn't justify the investment, especially when Mailmend offers guaranteed results at lower total cost of ownership.

6. Lemwarm — B2B Cold Email Warmup Integration

Lemwarm, integrated with the Lemlist outreach platform, provides specialized warmup for B2B cold email campaigns.

Features:

• Tight integration with Lemlist user base and workflows

• Automated warmup scheduling based on sending patterns

• Reputation building for new domains and email accounts

• Basic spam testing capabilities

Pricing Structure:

• Essential: $24/month per inbox (annual billing)

• Smart: $40/month annually or 49/month (advanced cluster targeting)

• Custom: Available for 10+ users

For B2B teams already using Lemlist, Lemwarm provides convenient integrated warmup. E-commerce brands using Klaviyo will find more value in solutions designed specifically for promotional email deliverability.

7. InboxAlly — Engagement Simulation Platform

InboxAlly focuses on simulating genuine engagement signals to improve sender reputation through behavioral automation.

Capabilities:

• Engagement simulation including opens, reads, and folder movements

• Reputation building through consistent engagement patterns

• Support for multiple email service providers

• Gradual reputation improvement over time

Pricing Structure:

• Entry: $149 monthly (100 seed emails daily)

• Mid-tier: $645 monthly (500 seed emails daily, 5 sender profiles)

• Enterprise: $1,190 monthly (1,000 seed emails daily, strategic advisory)

InboxAlly serves businesses prioritizing long-term sender reputation building. For e-commerce brands needing immediate Primary inbox placement, algorithmic solutions like Mailmend deliver faster, more measurable results.

Why E-commerce Brands Seek GlockApps Alternatives

GlockApps has built a solid reputation over 15+ years for comprehensive deliverability testing across multiple email providers. However, testing-only platforms present a fundamental limitation: they identify problems without solving them.

For e-commerce brands using Klaviyo, the core issue isn't spam folder placement—it's Gmail's Promotions tab. Even emails with perfect sender reputation land in Promotions, where open rates are significantly lower compared to Primary inbox placement.

Frequently Asked Questions

What are the main differences between GlockApps and Mailmend for e-commerce brands?

GlockApps provides comprehensive inbox placement testing across 20+ email service providers, identifying where emails land and why. However, it's a diagnostic tool—it tells you there's a problem but doesn't fix it. Mailmend takes a fundamentally different approach by using proprietary algorithmic code to actively move emails from Gmail's Promotions tab to Primary inbox. For e-commerce brands whose emails avoid spam but still underperform due to Promotions tab placement, Mailmend addresses the root cause while GlockApps only identifies the symptom.

How quickly can I see results from implementing inbox placement solutions like Mailmend?

Mailmend delivers measurable results within 24 hours of implementation, with brands like Ministry of Supply reporting improvements "within one business day." In contrast, warmup tools like Warmy.io and MailReach require 2-6 weeks before showing meaningful deliverability improvements. This timeline difference proves critical for e-commerce brands preparing for seasonal campaigns or product launches where every day of improved placement impacts revenue.

Do email deliverability tools require changes to my email content or existing campaigns?

Most warmup and testing tools work alongside your existing email setup without requiring content changes. Mailmend specifically preserves your email copy, design, and creative assets—its algorithmic code addresses Gmail's categorization signals at the technical level rather than modifying message content. This "zero changes" approach contrasts with traditional deliverability consulting that often recommends comprehensive content strategy overhauls.

Is Mailmend compatible with email service providers other than Klaviyo?

Currently, Mailmend operates exclusively with Klaviyo, the dominant ESP for e-commerce brands. This specialization enables deep integration with Klaviyo's template system, A/B testing functionality, and analytics dashboard. Brands using Mailchimp, Omnisend, or other ESPs would need to consider alternatives like GlockApps for testing or Warmy.io for warmup, though these don't address the Promotions tab challenge.

What is email warming and why is it important for deliverability?

Email warming gradually builds sender reputation by simulating engagement patterns (opens, reads, replies) over time. New domains or email accounts benefit from warmup before sending campaigns at scale. Platforms like Warmy.io maintain 35,000+ inbox networks for this purpose. However, warming addresses sender reputation—not Gmail's algorithmic categorization of promotional content. E-commerce brands with established reputation often find warming unnecessary; their challenge is Promotions tab placement, which requires different solutions.

How can I measure the ROI of improved inbox placement for my e-commerce business?

Mailmend's Klaviyo integration enables direct A/B testing: split your audience between emails with and without Mailmend's code to measure exact lift in open rates, click-through rates, and revenue attribution within your existing Klaviyo analytics dashboard. Documented case studies show revenue increases of 50-112% and CTR improvements of 43-67%, providing clear benchmarks for expected ROI.