Daniel Saks
Chief Executive Officer
Email deliverability hit crisis levels in 2025. Office365 inbox placement dropped to just 50.70%, and Mailgun plummeted 27.75 percentage points. For go-to-market teams, this isn't just a technical problem—it's a revenue emergency. The email deliverability tools market is projected to reach $2.03 billion by 2029 (10.4% CAGR), driven by mandatory authentication requirements from Gmail/Yahoo and the collapse of B2B inbox placement rates. While these fastest-growing email deliverability companies ensure your messages reach prospects, platforms like Landbase's audience discovery solve the upstream challenge—finding the right prospects to email in the first place using natural-language targeting.
Sublime Security develops agentic AI tools for email security, protecting enterprises from sophisticated phishing, business email compromise, and advanced email threats that bypass traditional filters. The platform uses cutting-edge AI to identify and neutralize threats before they reach users' inboxes.
Sublime Security addresses the $43 billion business email compromise problem with agentic AI that represents the cutting edge of threat detection. The company raised the largest Series C in email security for 2025 at $150M and achieved highest total funding in the sector at $240M, demonstrating investor confidence in their AI-powered approach. Email security is critical for GTM teams as business email compromise directly impacts revenue operations and customer trust.
Superhuman is a premium email client promising "the fastest email experience ever made" with AI-powered triage, browser-based architecture, and keyboard-first design. Users report saving 4+ hours per week on email management through intelligent prioritization and workflow automation.
Superhuman achieved cultural phenomenon status with a 180,000+ waitlist for only 15,000 active users, demonstrating premium market positioning at $260 million valuation. The $33M Series B led by Andreessen Horowitz signals strong VC confidence in AI-powered email productivity tools. For GTM teams, the 4-hour weekly time savings directly impacts sales productivity and email engagement rates.
ActiveCampaign is a customer experience automation platform integrating email marketing with sales CRM tools, automating personalized communication across the customer lifecycle. The platform boasts a 94.2% email deliverability rate—the highest among mainstream marketing platforms.
ActiveCampaign's 94.2% deliverability rate significantly exceeds the 83.1% industry average, critical for GTM teams where inbox placement directly impacts pipeline generation. The $360M total funding signals market dominance with 20+ year track record. The integrated CRM approach aligns with modern RevOps strategies demanding unified customer data and automation.
Klaviyo is an AI-first B2C CRM platform combining marketing automation, customer service (K:AI Customer Agent), and analytics specifically for e-commerce brands. The platform serves 193,000+ customer brands with deep integrations into Shopify, Salesforce, and other e-commerce platforms.
Klaviyo dominates e-commerce email marketing with successful IPO demonstrating market validation and 193,000+ customer brands showing massive scale. K:AI agents for both marketing content creation and 24/7 customer service represent future of automation. For GTM teams selling to e-commerce companies, Klaviyo integration is often a requirement, making understanding its capabilities essential.
Iterable is a cross-channel marketing automation platform (email, SMS, push, in-app) with AI-powered personalization and customer journey orchestration. The platform enables enterprises to coordinate messaging across multiple channels for consistent customer experiences.
Iterable's $342.2M total funding—second highest in email marketing category—demonstrates strong market validation. Cross-channel orchestration addresses modern customer journey complexity as GTM teams coordinate email, SMS, push notifications, and other channels. AI-powered journey orchestration ensures messaging consistency while optimizing for each channel's unique characteristics.
Nylas provides developers with universal APIs to integrate email, calendar, and contact functionality across all major providers (Gmail, Outlook, Exchange, iCloud). Known as "The Stripe of Email," the platform processes 34.5B+ API transactions and 200TB of data daily, serving 1,000+ enterprise customers.
Nylas reduces email integration development time by 90%, powering email for major enterprises including Salesforce, Upwork, and Wix. The $162.5M total funding including $60M Series C demonstrates investor confidence. Similar to how Stripe simplified payments, Nylas simplifies email/calendar integration for GTM platforms and SaaS applications.
Valimail is an automated email authentication platform (SPF, DKIM, DMARC) that prevents domain spoofing and business email compromise with one-click DMARC enforcement. The platform is the only FedRAMP-certified email authentication solution and serves 92,000+ businesses.
Valimail solves mandatory 2024 Gmail/Yahoo requirements and achieves 95%+ DMARC enforcement versus 20-60% for competitors. The $84M total funding and acquisition by DigiCert (September 16, 2025) validate technology and market position. Email authentication became mandatory for bulk senders in 2024, making Valimail's automated approach critical for GTM teams protecting sender reputation.
Front reimagines team email as a collaborative workspace with shared inboxes across email, SMS, Slack, and social media. The platform prevents duplicate responses with collision detection and processes over 1 billion messages annually for 9,000+ companies.
Front's $79.3M total funding including $66M Series B demonstrates market validation for shared inbox collaboration. Customer results include "7x faster response" (Y Combinator, Spruce) and "40% productivity increase" (Culture Amp). The platform's G2 Best Customer Service 2025 recognition confirms market leadership for GTM teams managing high-volume support and sales operations.
Cordial is a unified marketing and data platform enabling personalized real-time messaging across email and mobile channels. The platform integrates customer data from any source for highly relevant experiences with real-time personalization capabilities.
Cordial's $73.6M Series C signals strong growth trajectory addressing fragmented customer data challenges. Real-time personalization engine addresses growing customer expectations for contextual, relevant messaging. Data unification from any source solves critical challenge for modern GTM where customer touchpoints span multiple systems.
Resend is a developer-focused email API platform for transactional and marketing emails with React integration, managed dedicated IPs, and deliverability tools. The platform offers multi-region sending across North America, South America, Europe, and Asia to reduce delivery latency.
Resend's $18M Series A funding signals strong investor interest in developer-first email infrastructure. "Email for developers" positioning with React Email integration fills gap left by older platforms. Strong early customer adoption including Vercel demonstrates market validation. Managed dedicated IP auto-warmup and auto-scaling simplifies deliverability for fast-moving startups.
ZeroBounce is an email validation platform that removes invalid, disposable, spam traps, and harmful addresses from lists. The platform offers the industry's only full suite: verification, inbox placement testing, email server testing, and IP warmup—all with a 98% accuracy guarantee.
ZeroBounce achieved $10M revenue in 2024 with zero VC funding (bootstrapped success), demonstrating strong product-market fit. The 100,000+ customers demonstrates market leadership for list hygiene. With only 23.6% of B2B senders verifying lists before campaigns, ZeroBounce addresses critical deliverability factor. Platform validates against 6 billion email database for accuracy.
Warmy is an AI-powered email warm-up service that automatically warms domains/emails in 30+ languages, improves sender reputation, and offers deliverability testing. The platform specializes in topic-specific warm-up that matches business context for legitimate sending patterns.
Warmy achieved $8.4M revenue in 2024 with zero funding (profitable bootstrap), demonstrating strong market demand. The 30+ language support—only warm-up tool with this feature—enables global outreach. Topic-specific warm-up matching business vertical ensures legitimate engagement patterns. Proven customer results include Mangools: 1% to 32% open rate increase. Domain warm-up became critical after 2024 Gmail/Yahoo requirements.
While these fastest-growing email deliverability companies ensure your messages reach prospects' inboxes, the foundation of successful email outreach starts with targeting the right audience. Even with perfect deliverability, emailing unqualified prospects wastes resources and damages sender reputation over time.
This is where AI-powered audience discovery becomes essential. Landbase's platform allows GTM teams to build targeted prospect lists using natural-language prompts like "CFOs at enterprise SaaS companies that raised funding in the last 30 days." The platform leverages 1,500+ unique signals across firmographic, technographic, intent, and behavioral data to return AI-qualified audiences ready for immediate activation.
By combining high-quality audience targeting with best-in-class deliverability tools, GTM teams can maximize both inbox placement and engagement rates—turning the email deliverability crisis into a competitive advantage.
Email deliverability refers to the ability of your emails to reach recipients' inboxes rather than spam folders or getting blocked entirely. In 2025, Office365 inbox placement dropped to just 50.70%, meaning nearly half of emails never reach their intended audience. Poor deliverability directly impacts campaign performance by reducing the number of prospects who see your messages, thereby affecting lead generation, conversion rates, and revenue. Proper authentication, list hygiene, and sender reputation management are critical to maintaining high deliverability rates.
AI-powered tools enhance deliverability through intelligent email authentication (Valimail), advanced threat detection (Sublime Security), sender reputation management (Warmy), and automated list cleaning (ZeroBounce). These platforms use machine learning to identify patterns in email behavior, predict potential deliverability issues before they occur, and automatically optimize sending practices to maintain high inbox placement rates. AI can also personalize warm-up sequences and adapt to changing email provider requirements in real-time, ensuring consistent deliverability performance.
Look for solutions that address your specific needs: authentication platforms for compliance with 2024 Gmail/Yahoo requirements, verification tools for list hygiene, warm-up services for new domains, or comprehensive marketing platforms with built-in deliverability optimization. Consider factors like accuracy guarantees (such as ZeroBounce's 98% accuracy), ease of integration with your existing tech stack, proven customer results with documented case studies, and responsive customer support. Also evaluate whether the solution offers multi-language support if you operate globally, and check for features like real-time monitoring and detailed analytics.
Funding indicates investor confidence and provides resources for scaling, but isn't the only success metric to consider. Companies like Warmy ($8.4M revenue in 2024) and ZeroBounce ($10M revenue in 2024) demonstrate that bootstrapped, profitable companies can achieve significant market traction through strong product-market fit and customer satisfaction without venture capital. However, well-funded companies like Sublime Security ($240M total) can invest more aggressively in R&D, enterprise sales teams, and product innovation. Consider both funding and revenue metrics when evaluating a platform's stability and growth potential.
Absolutely—improving email deliverability can dramatically increase the number of prospects who actually see your messages, directly impacting pipeline generation and revenue. With only 23.6% of B2B senders verifying lists before campaigns, implementing proper authentication, list cleaning, and sender reputation management can give you a significant competitive advantage. When you improve deliverability from 50% to 90%, you're essentially doubling your reach without increasing send volume, which translates to more opportunities, meetings booked, and deals closed with the same outreach effort.
Tool and strategies modern teams need to help their companies grow.
