The Email Startup Graveyard: Why 80%+ of Email Companies Fail

The Email Startup Graveyard: Why 80%+ of Email Companies Fail While many email startups have invested millions in solving perceived problems, we at Forward Email have focused on building reliable email infrastructure from scratch since 2017. This analysis explores the patterns behind email startup outcomes and the fundamental challenges of email infrastructure. Note Key Insight: Most email startups don't build actual email infrastructure from scratch. Many build on top of existing solutions like Amazon SES or open-source systems like Postfix. The core protocols work well - the challenge is in the implementation. Building Modern Infrastructure for Existing Email Protocols: Our Approach Before diving into the failures, it's important to understand what actually works in email. The challenge isn't that email is broken - it's that most companies try to "fix" something that already works perfectly. The Email Innovation Spectrum Email innovation falls into three categories: Infrastructure Enhancement (What works): Building better servers, delivery systems, and developer tools Workflow Integration (Sometimes works): Adding email to existing business processes Protocol Replacement (Always fails): Trying to replace SMTP, IMAP, or POP3 Why We Focus on Infrastructure We chose to build modern email infrastructure because: Email protocols are proven : SMTP has worked reliably since 1982 : SMTP has worked reliably since 1982 The problem is implementation : Most email services use outdated software stacks : Most email services use outdated software stacks Users want reliability : Not new features that break existing workflows : Not new features that break existing workflows Developers need tools: Better APIs and management interfaces What Actually Works in Email The successful pattern is simple: enhance existing email workflows instead of replacing them. This means: Building faster, more reliable SMTP servers Creating better spam filtering without breaking legitimate email Providing developer-friendly APIs for existing protocols Improving deliverability through proper infrastructure The Email Startup Failure Matrix Here's every major email startup failure we could find, organized by accelerator, funding, and outcome: Caution Failure Rate: Techstars alone has 28 email-related companies with only 5 exits - an exceedingly high failure rate (sometimes calculated to be 80%+). The Infrastructure Reality Check Here's what nobody talks about: every single "email startup" is just building UI on top of existing infrastructure. What Actually Runs Email Amazon SES : Powers most "email APIs" and services : Powers most "email APIs" and services Postfix : The actual SMTP server running everywhere : The actual SMTP server running everywhere Cyrus IMAP : What handles your actual email storage : What handles your actual email storage SpamAssassin : What filters your spam : What filters your spam DKIM/SPF/DMARC: The authentication that actually works What "Email Startups" Actually Build React Native apps with memory leaks Web interfaces that break email threading "AI" features that Gmail already has "Security" layers that break existing workflows APIs that wrap Amazon SES with 10x markup Tip Key Pattern for Email Success: The companies that actually succeed in email don't try to reinvent the wheel. Instead, they build infrastructure and tools that enhance existing email workflows. SendGrid, Mailgun, and Postmark became billion-dollar companies by providing reliable SMTP APIs and delivery services - they work with email protocols, not against them. This is the same approach we take at Forward Email. Case Study: The Skiff Disaster Skiff perfectly exemplifies everything wrong with email startups. The Setup Positioning : "Privacy-first email and productivity platform" : "Privacy-first email and productivity platform" Funding : Significant venture capital : Significant venture capital Promise: Better email through privacy and encryption The Acquisition Notion acquired Skiff in February 2024 with typical acquisition promises about integration and continued development. The Reality Immediate shutdown : Skiff shut down within months : Skiff shut down within months Founder exodus : Skiff founders left Notion and joined Cursor : Skiff founders left Notion and joined Cursor User abandonment: Thousands of users forced to migrate The Accelerator Analysis Y Combinator: The Email App Factory Y Combinator has funded dozens of email startups. Here's the pattern: Emailio (2014): Mobile email client → pivoted to "wellness" (2014): Mobile email client → pivoted to "wellness" MailTime (2016): Chat-style email → pivoted to analytics (2016): Chat-style email → pivoted to analytics reMail (2009): iPhone email search → acquired by Google → shutdown (2009): iPhone email search → acquired by Google → shutdown Rapportive (2012): Gmail social profiles → acquired by LinkedIn → shutdown Success Rate: Several large acquisitions. Most pivot away from email or get acqui-hired. Techstars: The Email Graveyard Techstars has an even worse track record: Email Copilot (2012): Acquired → shutdown (2012): Acquired → shutdown ReplySend (2012): Failed completely (2012): Failed completely Nveloped (2012): "Easy. Secure. Email" → failed (2012): "Easy. Secure. Email" → failed Jumble (2015): Email encryption → failed (2015): Email encryption → failed InboxFever (2011): Email API → failed Pattern: Vague value propositions, no real technical innovation, quick failures. Why Email Startups Always Fail 1. Email Isn't Broken The fundamental assumption is wrong. Email works perfectly: Universal compatibility : Every device, every platform : Every device, every platform Dummy-proof : Status codes (e.g. 421) and queues allow retries : Status codes (e.g. 421) and queues allow retries Standardized : SMTP, IMAP, POP3 are battle-tested : SMTP, IMAP, POP3 are battle-tested Reliable: Billions of emails sent daily without issues 2. Network Effects Are Unbreakable Email's network effect is absolute: Everyone has email : 4+ billion email users worldwide : 4+ billion email users worldwide Cross-platform : Works between all providers : Works between all providers Business critical : Companies depend on email reliability : Companies depend on email reliability Switching cost: Changing email addresses breaks everything 3. They're Solving Non-Problems Most email startups target imaginary issues: "Email is too complex" : It's not. Send, receive, organize. : It's not. Send, receive, organize. "Email needs AI" : Gmail already has smart features : Gmail already has smart features "Email needs better security" : DKIM/SPF/DMARC work fine : DKIM/SPF/DMARC work fine "Email needs a new interface": Outlook/Gmail interfaces are optimized 4. Technical Debt Is Massive Building real email infrastructure requires: SMTP servers : Complex delivery and reputation management : Complex delivery and reputation management Spam filtering : Constantly evolving threat landscape : Constantly evolving threat landscape Storage systems : Reliable IMAP/POP3 implementation : Reliable IMAP/POP3 implementation Authentication : DKIM, SPF, DMARC, ARC compliance : DKIM, SPF, DMARC, ARC compliance Deliverability: ISP relationships and reputation management 5. The Infrastructure Already Exists Why reinvent when you can use: Amazon SES : Proven delivery infrastructure : Proven delivery infrastructure Postfix : Battle-tested SMTP server : Battle-tested SMTP server Dovecot : Reliable IMAP/POP3 server : Reliable IMAP/POP3 server SpamAssassin : Effective spam filtering : Effective spam filtering Existing providers: Gmail, Outlook, FastMail work fine The Venture Capital Trap VCs love email startups because they sound simple but are actually impossible: Large market : "Everyone uses email!" : "Everyone uses email!" Clear problem : "Email is old and broken!" : "Email is old and broken!" Technical moat : "We'll build better infrastructure!" : "We'll build better infrastructure!" Network effects: "Once we get users, we'll dominate!" Reality: None of these assumptions hold true for email. The Technical Reality: Modern Email Stacks What Actually Powers "Email Startups" Let's look at what these companies actually run: # What most "email startups" actually run [ React Native App ] → [ Node .js API ] → [ Amazon SES ] → [ Existing Email Infrastructure ] [ 100 % Custom Node. js JavaScript Stack Built From Scratch] * Our technical whitepaper explains our complete infrastructure The Performance Problems Memory Bloat: Most email apps are Electron-based web apps that consume massive amounts of RAM: Mailspring : 500MB+ for basic email : 500MB+ for basic email Nylas Mail : 1GB+ memory usage : 1GB+ memory usage Postbox : 300MB+ idle memory : 300MB+ idle memory Canary Mail: Frequent crashes due to memory issues Battery Drain: Constant syncing and inefficient code: Background processes that never sleep Unnecessary API calls every few seconds Poor connection management No third-party dependencies except those absolutely required for core functionality The Acquisition-to-Shutdown Pipeline The Standard Pattern Launch: "Revolutionary email experience" Funding: Raise $5-50M from VCs Growth: Acquire some users, burn through cash Acquisition: Larger company buys for talent/features Integration: "We're excited to integrate..." Shutdown: Service discontinued within 12 months Recent Examples Mailbox → Dropbox → Shutdown (2013-2015) (2013-2015) Sparrow → Google → Shutdown (2012-2013) (2012-2013) reMail → Google → Shutdown (2010-2011) (2010-2011) Skiff → Notion → Shutdown (2024) Industry Evolution and Consolidation Natural Industry Progression The email industry has naturally evolved toward consolidation, with larger companies acquiring smaller ones to integrate features or eliminate competition. This isn't necessarily negative - it's how most mature industries develop. Post-Acquisition Transitions When email companies are acquired, users often face: Service migrations : Moving to new platforms : Moving to new platforms Feature changes : Loss of specialized functionality : Loss of specialized functionality Pricing adjustments : Different subscription models : Different subscription models Integration periods: Temporary service disruptions User Considerations During Transitions During industry consolidation, users benefit from: Evaluating alternatives : Multiple providers offer similar services : Multiple providers offer similar services Understanding migration paths : Most services provide export tools : Most services provide export tools Considering long-term stability: Established providers often offer more continuity The Hacker News Reality Check Every email startup gets the same comments on Hacker News: The community is right. These comments appear on every email startup launch because the fundamental problems are always the same. The Modern AI Email Grift The Latest Wave 2024 brought a new wave of "AI-powered email" startups: Superhuman : $33M raised, AI features on top of Gmail : $33M raised, AI features on top of Gmail Shortwave : Gmail wrapper with AI summaries : Gmail wrapper with AI summaries SaneBox: AI email filtering (actually works, but not revolutionary) The Same Old Problems Adding "AI" doesn't solve email's fundamental non-problems: AI summaries : Most emails are already short : Most emails are already short Smart replies : Gmail has had these for years : Gmail has had these for years Email scheduling : Outlook does this natively : Outlook does this natively Priority detection: Every email client has filters What Actually Works: The Real Email Success Stories Infrastructure Companies (The Winners) SendGrid : $3B acquisition by Twilio : $3B acquisition by Twilio Mailgun : $50M+ revenue, acquired by Sinch : $50M+ revenue, acquired by Sinch Postmark : Profitable, acquired by ActiveCampaign : Profitable, acquired by ActiveCampaign Amazon SES: Billions in revenue Pattern: They build infrastructure, not apps. Email Providers (The Survivors) FastMail : 25+ years, profitable, independent : 25+ years, profitable, independent ProtonMail : Privacy-focused, sustainable growth : Privacy-focused, sustainable growth Zoho Mail : Part of larger business suite : Part of larger business suite Forward Email (us): 7+ years, profitable, growing Pattern: They enhance email, don't replace it. The Exception: Xobni's Success Story Xobni stands out as one of the few email-related startups that actually succeeded by taking the right approach. What Xobni Did Right: Enhanced existing email : Built on top of Outlook instead of replacing it : Built on top of Outlook instead of replacing it Solved real problems : Contact management and email search : Contact management and email search Focused on integration : Worked with existing workflows : Worked with existing workflows Enterprise focus: Targeted business users with real pain points The Success: Xobni was acquired by Yahoo for $60 million in 2013, providing a solid return for investors and a successful exit for founders. Why Xobni Succeeded Where Others Failed Built on proven infrastructure: Used Outlook's existing email handling Solved actual problems: Contact management was genuinely broken Enterprise market: Businesses pay for productivity tools Integration approach: Enhanced rather than replaced existing workflows The Founders' Continued Success Matt Brezina and Adam Smith didn't stop after Xobni: Matt Brezina : Became an active angel investor with investments in Dropbox, Mailbox, and others : Became an active angel investor with investments in Dropbox, Mailbox, and others Adam Smith : Continued building successful companies in the productivity space : Continued building successful companies in the productivity space Both founders: Demonstrated that email success comes from enhancement, not replacement The Pattern Companies succeed in email when they: Build infrastructure (SendGrid, Mailgun) Enhance existing workflows (Xobni, FastMail) Focus on reliability (Amazon SES, Postmark) Serve developers (APIs and tools, not end-user apps) Has Anyone Successfully Reinvented Email? This is a crucial question that gets to the heart of email innovation. The short answer is: no one has successfully replaced email, but some have successfully enhanced it. What Actually Stuck Looking at email innovations over the past 20 years: Gmail's threading : Enhanced email organization : Enhanced email organization Outlook's calendar integration : Enhanced scheduling : Enhanced scheduling Mobile email apps : Enhanced accessibility : Enhanced accessibility DKIM/SPF/DMARC: Enhanced security Pattern: All successful innovations enhanced existing email protocols rather than replacing them. New Tools Complement Email (But Don't Replace It) Slack : Great for team chat, but still sends email notifications : Great for team chat, but still sends email notifications Discord : Excellent for communities, but uses email for account management : Excellent for communities, but uses email for account management WhatsApp : Perfect for messaging, but businesses still use email : Perfect for messaging, but businesses still use email Zoom: Essential for video calls, but meeting invites come via email Hey.com by Basecamp represents the most serious recent attempt to "reinvent" email: Launched : 2020 with significant fanfare : 2020 with significant fanfare Approach : Completely new email paradigm with screening, bundling, and workflows : Completely new email paradigm with screening, bundling, and workflows Reception : Mixed - some love it, most stick with existing email : Mixed - some love it, most stick with existing email Reality: It's still email (SMTP/IMAP) with a different interface Interesting Note: Hey.com's founder DHH actually uses our service at Forward Email for his personal domain dhh.dk and has for several years, demonstrating that even email innovators rely on proven infrastructure. What Actually Works The most successful email innovations have been: Better infrastructure: Faster servers, better spam filtering, improved deliverability Enhanced interfaces: Gmail's conversation view, Outlook's calendar integration Developer tools: APIs for sending email, webhooks for tracking Specialized workflows: CRM integration, marketing automation, transactional email None of these replaced email - they made it better. Our Approach: Why We're Different What We Do Build actual infrastructure : Custom SMTP/IMAP servers from scratch : Custom SMTP/IMAP servers from scratch Focus on reliability : 99.99% uptime, proper error handling : 99.99% uptime, proper error handling Enhance existing workflows : Work with all email clients : Work with all email clients Serve developers : APIs and tools that actually work : APIs and tools that actually work Maintain compatibility: Full SMTP/IMAP/POP3 compliance What We Don't Do Build "revolutionary" email clients Try to replace existing email protocols Add unnecessary AI features Promise to "fix" email How We Build Email Infrastructure That Actually Works Our Anti-Startup Approach While other companies burn millions trying to reinvent email, we focus on building reliable infrastructure: No pivots : We've been building email infrastructure for 7+ years : We've been building email infrastructure for 7+ years No acquisition strategy : We're building for the long term : We're building for the long term No "revolutionary" claims: We just make email work better What Makes Us Different Technical Stack: [postfix + custom-encryption + web- interface ] = APNIC blog post confirms Proton uses postfix-mta-sts-resolver, indicating they run a Postfix stack Our Stack: [ 100 % Custom Node. js JavaScript Stack Built From Scratch] Key Differences: Modern language : JavaScript across the entire stack vs. 1980s C code : JavaScript across the entire stack vs. 1980s C code No glue code : Single language eliminates integration complexity : Single language eliminates integration complexity Web-native : Built for modern web development from the ground up : Built for modern web development from the ground up Maintainable : Any web developer can understand and contribute : Any web developer can understand and contribute No legacy debt: Clean, modern codebase without decades of patches The Technical Timeline 2017 : Started building custom SMTP server : Started building custom SMTP server 2018 : Added IMAP support and spam filtering : Added IMAP support and spam filtering 2019 : Implemented DKIM/SPF/DMARC authentication : Implemented DKIM/SPF/DMARC authentication 2020 : Added PGP encryption and security features : Added PGP encryption and security features 2021 : Built custom DNS management system : Built custom DNS management system 2022 : Implemented advanced anti-spam measures : Implemented advanced anti-spam measures 2023 : Added enterprise features and API : Added enterprise features and API 2024: Reached profitability and sustainable growth Why We Succeed Where Others Fail We build infrastructure, not apps: Focus on servers and protocols We enhance, don't replace: Work with existing email clients We're profitable: No VC pressure to "grow fast and break things" We understand email: 7+ years of deep technical experience We serve developers: APIs and tools that actually solve problems The Cost Reality Check Typical Email Startup Burn Rate: $500K-2M per month in VC funding 20-50 employees Expensive office space and perks Marketing and customer acquisition costs Our Approach: Profitable from day one Small, focused team Remote-first, low overhead Organic growth through word-of-mouth Security Challenges in Email Infrastructure Email security is a complex challenge that affects all providers in the industry. Rather than highlighting individual incidents, it's more valuable to understand the common security considerations that all email infrastructure providers must address. Common Security Considerations All email providers face similar security challenges: Data protection : Securing user data and communications : Securing user data and communications Access control : Managing authentication and authorization : Managing authentication and authorization Infrastructure security : Protecting servers and databases : Protecting servers and databases Compliance: Meeting various regulatory requirements The Value of Transparency When security incidents occur, the most valuable response is transparency and quick action. Companies that: Disclose incidents promptly : Help users make informed decisions : Help users make informed decisions Provide detailed timelines : Show they understand the scope of issues : Show they understand the scope of issues Implement fixes quickly : Demonstrate technical competence : Demonstrate technical competence Share lessons learned: Contribute to industry-wide security improvements These responses benefit the entire email ecosystem by promoting best practices and encouraging other providers to maintain high security standards. Ongoing Security Challenges The email industry continues to evolve its security practices: Encryption standards : Implementing better encryption methods : Implementing better encryption methods Authentication protocols : Improving DKIM, SPF, and DMARC : Improving DKIM, SPF, and DMARC Threat detection : Developing better spam and phishing filters : Developing better spam and phishing filters Infrastructure hardening: Securing servers and databases These challenges require ongoing investment and expertise from all providers in the space. Conclusion: Stop Building Email Apps The Evidence Is Overwhelming After analyzing hundreds of email startups: 80%+ failure rate : Most email startups fail completely : Most email startups fail completely Acquisition = shutdown : Being acquired usually means death : Being acquired usually means death VC funding = pressure : Venture capital creates unrealistic expectations : Venture capital creates unrealistic expectations Technical debt = unsustainable: Building email infrastructure is harder than it looks The Historical Context Email has been "dying" for 20+ years according to startups: 2004 : "Social networks will replace email" : "Social networks will replace email" 2008 : "Mobile messaging will kill email" : "Mobile messaging will kill email" 2012 : "Slack will replace email" : "Slack will replace email" 2016 : "AI will revolutionize email" : "AI will revolutionize email" 2020 : "Remote work needs new communication tools" : "Remote work needs new communication tools" 2024: "AI will finally fix email" Email is still here. It's still growing. It's still essential. The Real Lesson The lesson isn't that email can't be improved. It's that: Email protocols work: SMTP, IMAP, POP3 are battle-tested Infrastructure matters: Reliability beats features Enhancement beats replacement: Work with email, don't fight it Sustainability beats growth: Profitable businesses outlast VC-funded ones If you're thinking about building an email startup, consider building email infrastructure instead. The world needs better email servers, not more email apps. The Extended Email Graveyard: More Failures and Shutdowns Google's Email Experiments Gone Wrong Google, despite owning Gmail, has killed multiple email projects: Google Wave (2009-2012): "Email killer" that nobody understood (2009-2012): "Email killer" that nobody understood Google Buzz (2010-2011): Social email integration disaster (2010-2011): Social email integration disaster Inbox by Gmail (2014-2019): Gmail's "smart" successor, abandoned (2014-2019): Gmail's "smart" successor, abandoned Google+ email features (2011-2019): Social network email integration Pattern: Even Google can't successfully reinvent email. The Serial Failure: Newton Mail's Three Deaths Newton Mail died three times: CloudMagic (2013-2016): Email client acquired by Newton Newton Mail (2016-2018): Rebranded, subscription model failed Newton Mail Revival (2019-2020): Attempted comeback, failed again Lesson: Email clients can't sustain subscription models. The Apps That Never Launched Many email startups died before launching: Tempo (2014): Calendar-email integration, shut down pre-launch (2014): Calendar-email integration, shut down pre-launch Mailstrom (2011): Email management tool, acquired before release (2011): Email management tool, acquired before release Fluent (2013): Email client, development stopped The Acquisition-to-Shutdown Pattern Sparrow → Google → Shutdown (2012-2013) (2012-2013) reMail → Google → Shutdown (2010-2011) (2010-2011) Mailbox → Dropbox → Shutdown (2013-2015) (2013-2015) Accompli → Microsoft → Shutdown (became Outlook Mobile) (became Outlook Mobile) Acompli → Microsoft → Integrated (rare success) Email Infrastructure Consolidation Postbox → eM Client (2024): Postbox immediately shut down after acquisition (2024): Postbox immediately shut down after acquisition Multiple acquisitions : ImprovMX has been acquired multiple times : ImprovMX has been acquired multiple times Service degradation: Many services get worse after acquisition The Open-Source Email Graveyard: When "Free" Isn't Sustainable Nylas Mail → Mailspring: The Fork That Couldn't Nylas Mail : Open-source email client, discontinued 2017 : Open-source email client, discontinued 2017 Mailspring : Community fork, struggling with maintenance : Community fork, struggling with maintenance Reality: Open-source email clients can't compete with native apps Eudora: The 18-Year Death March 1988-2006 : Dominant email client for Mac/Windows : Dominant email client for Mac/Windows 2006 : Qualcomm stopped development : Qualcomm stopped development 2007 : Open-sourced as "Eudora OSE" : Open-sourced as "Eudora OSE" 2010 : Project abandoned : Project abandoned Lesson: Even successful email clients eventually die FairEmail: Killed by Google Play Politics FairEmail : Privacy-focused Android email client : Privacy-focused Android email client Google Play : Banned for "violating policies" : Banned for "violating policies" Reality: Platform policies can kill email apps instantly The Maintenance Problem Open-source email projects fail because: Complexity : Email protocols are complex to implement correctly : Email protocols are complex to implement correctly Security : Constant security updates required : Constant security updates required Compatibility : Must work with all email providers : Must work with all email providers Resources: Volunteer developers can't sustain enterprise-level software The AI Email Startup Surge: History Repeating with "Intelligence" The Current AI Email Gold Rush 2024's AI email startups: Superhuman : $33M raised, AI features on Gmail : $33M raised, AI features on Gmail Shortwave : Y Combinator, Gmail + AI : Y Combinator, Gmail + AI SaneBox : AI email filtering (actually profitable) : AI email filtering (actually profitable) Boomerang : AI scheduling and responses : AI scheduling and responses Mail-0/Zero : AI-powered email client startup building yet another email interface : AI-powered email client startup building yet another email interface Inbox Zero: Open-source AI email assistant attempting to automate email management The Funding Frenzy VCs are throwing money at "AI + Email": $100M+ invested in AI email startups in 2024 invested in AI email startups in 2024 Same promises : "Revolutionary email experience" : "Revolutionary email experience" Same problems : Building on top of existing infrastructure : Building on top of existing infrastructure Same outcome: Most will fail within 3 years Why They'll All Fail (Again) AI doesn't solve email's non-problems: Email works fine Gmail already has AI: Smart replies, priority inbox, spam filtering Privacy concerns: AI requires reading all your emails Cost structure: AI processing is expensive, email is commodity Network effects: Can't break Gmail/Outlook dominance The Inevitable Outcome 2025-2026 : Most AI email startups will pivot or shut down : Most AI email startups will pivot or shut down 2027 : Survivors will be acquired and shut down : Survivors will be acquired and shut down 2028: "Blockchain email" will be the next trend The Consolidation Catastrophe: When "Survivors" Become Disasters The Great Email Service Consolidation The email industry has consolidated dramatically: ActiveCampaign acquired Postmark (2022) (2022) Sinch acquired Mailgun (2021) (2021) Twilio acquired SendGrid (2019) (2019) Multiple ImprovMX acquisitions (ongoing) Outlook: The "Survivor" That Can't Stop Breaking Microsoft Outlook, despite being a "survivor," has constant issues: Memory leaks : Outlook consumes gigabytes of RAM : Outlook consumes gigabytes of RAM Sync problems : Emails disappear and reappear randomly : Emails disappear and reappear randomly Performance issues : Slow startup, frequent crashes : Slow startup, frequent crashes Compatibility problems: Breaks with third-party email providers Our Real-World Experience: We regularly help customers whose Outlook setups break our perfectly compliant IMAP implementation. The Postmark Infrastructure Problem After ActiveCampaign's acquisition: Recent Email Client Casualties (2024-2025) Postbox → eM Client Acquisition: In 2024, eM Client acquired Postbox and immediately shut it down, forcing thousands of users to migrate. Canary Mail Issues: Despite Sequoia backing, users report non-working features and poor customer support. Spark by Readdle: Users increasingly report poor experience with the email client. Mailbird Licensing Problems: Windows users face licensing issues and subscription confusion. Airmail Decline: The Mac/iOS email client, based on the failed Sparrow codebase, continues to receive poor reviews for reliability issues. Email Extension and Service Acquisitions HubSpot Sidekick → Discontinued: HubSpot's email tracking extension was discontinued in 2016 and replaced with "HubSpot Sales." Engage for Gmail → Retired: Salesforce's Gmail extension was retired in June 2024, forcing users to migrate to other solutions. The Survivors: Email Companies That Actually Work Not all email companies fail. Here are the ones that actually work: Mailmodo: Y Combinator success story that raised $2M from Sequoia's Surge by focusing on interactive email campaigns. Mixmax: Raised $13.3M total funding and continues operating as a successful sales engagement platform. Outreach.io: Reached $1.33B+ valuation and is preparing for potential IPO as a sales engagement platform. Apollo.io: Achieved $1.6B valuation with $100M Series D in 2023 for their sales intelligence platform. GMass: Bootstrap success story generating $140K/month as a Gmail extension for email marketing. Streak CRM: Successful Gmail-based CRM that's been operating since 2012 without major issues. ToutApp: Successfully acquired by Marketo in 2017 after raising $15M+ in funding. Bananatag: Acquired by Staffbase in 2021 and continues operating as "Staffbase Email." Key Pattern: These companies succeed because they enhance existing email workflows rather than trying to replace email entirely. They build tools that work with email infrastructure, not against it.