Every email that never reaches an inbox is a sale, a review, or a repeat customer that never happened. It's an order confirmation your customer never saw, a win-back offer that never landed. And it's happening more than most store owners realise: across the industry, average inbox placement in 2026 sits somewhere in the mid-to-high 80s depending on which benchmark report you read, implying that a meaningful slice of commercial email is going nowhere. Retail and eCommerce senders tend to sit below that average, largely because of high promotional send volume.
Email marketing is still one of the highest-return channels available to retailers, but only if your messages actually land.
The good news is that this is mostly within your control, and the fix doesn't need a developer. Since Gmail and Yahoo introduced their bulk sender requirements in February 2024, which was matched in spirit by Apple and Microsoft, the rules have become clearer, even if the bar is higher. Get the fundamentals right and you're most of the way there.
Here are nine ways to make sure your emails actually reach your customers in 2026.
This is the step that didn't exist a few years ago, and it's now the first thing to check before touching anything else.
Gmail and Yahoo now require bulk senders to have SPF, DKIM, and DMARC properly configured - no exceptions, and no more sneaking through the spam filter if you skip it. Gmail has moved from filtering non-compliant bulk mail to rejecting it outright. Apple and Microsoft have followed a similar path, and Apple in particular tends to fail silently: instead of a message landing in spam where a customer might notice it days later, it simply never arrives, with no bounce and no warning to either of you.
Our partners at Waypoint recently wrote a great breakdown of this exact problem after several of their own Shopify orders went silent. No confirmation, no receipt, nothing. Their diagnosis lines up with what we see too: it's rarely one broken thing, it's an unauthenticated sending domain quietly failing checks at the recipient's end, and every automated email from that domain, including order confirmations, shipping updates, and support replies going down with it. Worth a read if you want the full story of how they tracked it down, including why tools like Marsello and Klaviyo need their own domain authentication on top of your main sending platform.
What to do about it:
What this protects, in plain terms: every order confirmation, shipping update, and win-back email you send depends on this being set up correctly. Get it wrong and none of your other marketing matters, because it's never reaching the customer.
If you're on Marsello, this is a five-minute job: a custom sending domain is built into every plan, and our help centre walkthrough takes you through adding the records step by step. If you're on a different platform, your provider's support docs will have the equivalent guide... the principle is the same everywhere.
Once authentication is sorted, reputation is the next lever. Inbox providers score both your sending domain and your IP address, and a poor score gets you routed straight to spam regardless of how good your content is.
Spam traps are addresses inbox providers use specifically to catch senders with sloppy list hygiene. Hit one and it can damage your reputation fast.
It feels counterintuitive, but a frictionless unsubscribe link protects your deliverability more than it costs you in list size. Since 2024, Gmail and Yahoo have required one-click unsubscribe for bulk senders, so this isn't optional anymore. When people can't unsubscribe easily, they hit "Report Spam" instead, and that complaint hurts your reputation far more than a lost subscriber ever would.
If your brand is "Bloom Skincare," don't send it from "Jane Smith." Use something customers will recognize instantly. "Bloom Skincare" or "Jane from Bloom Skincare" both work well. Recognition drives opens; unrecognized senders drive deletes and spam reports, and both feed back into your reputation.
Subject lines that promise something the email doesn't deliver will get you marked as spam even if they get the open. Be compelling, but be accurate.
Filters still weight certain words and formatting more heavily, particularly:
This matters far less than it used to. Modern filters lean overwhelmingly on your sending reputation and how people engage, not a banned-word list, but a few habits still count against you, particularly:
Irregular sending patterns can look suspicious to filters and unfamiliar to subscribers. Test different cadences, find what your audience responds to, and stick with it rather than changing frequency on a whim.
Open rates are increasingly unreliable, since Apple Mail Privacy Protection pre-fetches images (including tracking pixels) for the majority of Apple Mail users regardless of whether someone actually opens the email. Shift your primary attention to:
Authentication is the step that changed the most since we first wrote about this topic, and it's now the one to get right before anything else on this list. If you haven't checked your SPF, DKIM, and DMARC setup recently, that's the place to start. Our help center guide walks through it step by step, and it's worth pairing with Waypoint's writeup if you're on Shopify and want the full picture of how these failures show up for customers on the other end.
Get the technical foundation right, keep your list clean, and send messages people actually want - and your deliverability (and your revenue) will follow.
See what's actually landing. Marsello's reporting shows you open, click, and revenue performance for every campaign so you're not guessing whether your emails are reaching customers, you can see it. Explore Marsello's email tools →