Why Gmail and Outlook are Silently Killing Your Business
Why Gmail and Outlook are Silently Killing Your Business
Hans Desjarlais
May 29, 2026<br>8 min read
If your business sends emails, transactional or marketing, you'll want to pay attention because this directly impacts your bottom line.<br>What I've observed in the last 4 years isn't good and the frustration is real.<br>Since 2022 I’ve performed hundreds of audits and consultations for businesses wanting to stop landing in spam, and start landing in the inbox.<br>Most of my clients come from a checklist I launched on Hacker News 4 years ago and Upwork, where I’ve maintained a 100% job success rate and reached Top Rated status (not an easy feat to accomplish if you know Upwork).<br>I’m not just some guy that wrote a deliverability checklist once upon a time and considers himself an “expert”.<br>I don't consider myself an expert. No one is.<br>I'm just a guy on the bleeding edge who's been in the trenches, having conversations with hundreds of businesses about the real challenges they face.<br>And I can tell you, what I’m seeing isn’t good and the frustration is real!<br>Here’s what I’ve observed in the last 4 years:<br>70% of consumers use Gmail (Outlook/Hotmail/Live & Yahoo account for the rest)
95% of small businesses use Google Workspace (5% use Office 365)
Most businesses are unaware they have deliverability problems.
The landscape has changed, Google and Microsoft now control it.
ESPs built their entire business models during a time when deliverability wasn’t even an issue, and is now treated as an afterthought.
Tech fatigue is real — people are tired of constantly figuring things out.
Most deliverability tools throw a bunch of data at you and expect you to figure it out.
Most businesses can’t afford to hire a full time deliverability specialist.
The knowledge gap is real — even seasoned marketers are taken by surprise.
Deliverability isn’t something you set up once and forget, you have to monitor it constantly.
You can do everything right but if you make one mistake, you can still lose.
Let me start with the biggest shift, because it explains almost everything else.<br>The Duopoly: A Silent Tax on Your Business<br>When I started my career in tech, most businesses ran their own mail server on a cPanel account, with an open-source spam filter called SpamAssassin doing the filtering. That world is gone.<br>On the consumer side, Gmail launched in 2004 and gradually took over.<br>By 2015 it had overtaken Hotmail as the most popular US email provider, and today roughly three-quarters of US adults aged 18–64 use it.<br>Source: https://www.statista.com/chart/34197/share-of-us-respondents-use-email-providers/<br>The business market consolidated along the same lines, just a few years behind.<br>Google launched G Suite (now Google Workspace) in 2006.<br>Microsoft responded with Office 365 in 2011.<br>Today those two products account for roughly 95% of the business productivity software market — Google owns SMB and education, Microsoft owns the enterprise.<br>Two companies now sit between your business and every email it sends.<br>Spam filtering tells the same story.<br>Gmail, Outlook, and Yahoo all run proprietary systems that analyze thousands of signals — engagement history, sender reputation, authentication alignment, complaint rates.<br>In February 2024 this got a lot more concrete.<br>Google and Yahoo rolled out new requirements for senders pushing more than 5,000 emails per day: SPF, DKIM, and DMARC became mandatory, one-click unsubscribe was required, and spam complaint rates had to stay below 0.10% in Postmaster Tools.<br>Cross 0.30% and your mail gets rejected outright.<br>From November 2025, Gmail tightened enforcement further.<br>That's what makes this a tax rather than a fee.<br>Google and Microsoft don't just host your inbox and your customers' inboxes — they now decide which of your emails reach them.<br>Get on their wrong side and your sales pipeline can go dark overnight.<br>The cost isn't the per-seat licensing line on your invoice.<br>It's the dependence on two companies whose deliverability rules you have to learn, follow, and re-learn every time they change them.<br>And from the hundreds of conversations I've had with clients, most businesses don't have the bandwidth to monitor this consistently.<br>Your Email Service Provider Isn’t Built to Help You<br>Here's a scenario I see play out with my clients all the time:<br>Client: "How can we improve our open rate?"<br>ESP: "Here's a link to our deliverability documentation."<br>Client: "Okay, it says we need to generate engagement. But how do we generate engagement if our emails are going to spam?"<br>ESP: "…you need to generate engagement."<br>Client: "???"<br>I call this the Catch-22 of modern email.<br>Businesses get caught off guard by the changing landscape and the duopoly's latest rule changes, and suddenly they're stuck.<br>How do you generate engagement if your subscribers never see your emails?<br>I recently audited an EdTech company in Los Angeles.<br>They send regular informational emails to...