A well-written email that lands in spam does nothing. Deliverability is the part of Shopify email marketing that gets the least attention and causes the most quiet damage, because it fails silently — nobody tells you your welcome series is landing in the promotions tab or the spam folder, your open rates just look worse than they should, and it’s easy to blame the subject lines instead of the plumbing underneath them.
1. Why deliverability problems hide in plain sight
A dropping open rate looks like a content problem — a weak subject line, the wrong send time, list fatigue. Sometimes it is. But if opens have been sliding gradually across every campaign regardless of what you’re sending, the more likely explanation is that a growing share of your list simply isn’t seeing the email at all. Content problems are inconsistent from send to send; deliverability problems are consistent and slow-building.
2. The three records that authenticate your email
Inbox providers decide whether to trust an email partly based on whether the sending domain has proven it’s actually authorized to send on your behalf. Three DNS records do that:
- SPF — lists which mail servers are allowed to send email for your domain
- DKIM — attaches a cryptographic signature to outgoing email so receiving servers can verify it wasn’t altered or spoofed in transit
- DMARC — tells receiving servers what to do if a message fails SPF or DKIM, and lets you see reports when it happens
Most email platforms will show you clearly whether these are set up correctly for your sending domain, usually in a domain authentication or sending settings screen. If any of the three show as unverified, that’s worth fixing before touching anything else on this list — it’s foundational to whether your email gets delivered at all.
3. List hygiene matters more than list size
A large list full of addresses that never open anything actively hurts you — inbox providers watch engagement rates, and consistently emailing people who never open or click signals that your mail might not be wanted, which can drag deliverability down for your entire list, including the subscribers who do want to hear from you. A few practical habits:
- Suppress or re-engage subscribers who haven’t opened anything in 90+ days, rather than emailing them at the same rate as active subscribers
- Remove hard bounces immediately — an email address that bounces once will usually keep bouncing
- Avoid buying or importing lists from outside your own store’s opt-ins, no matter how targeted the source claims to be
4. Sending patterns that build or damage trust
Inbox providers also watch how consistently and predictably you send. A few patterns tend to help:
- Consistent volume — a sudden jump from a few campaigns a month to daily sends can look like your account was compromised or repurposed for spam
- Warming up a new sending domain gradually — start with smaller, highly engaged segments before sending to your full list
- Avoiding spam-trigger patterns in content — excessive exclamation points, all-caps subject lines, and link-heavy emails with little text all correlate with spam filtering, even when the email is legitimate
5. What to check on your Shopify store’s email setup this week
If you’ve never audited deliverability, three checks cover most of what matters: confirm SPF/DKIM/DMARC show as verified in your email platform’s domain settings, check your engagement rate trend over the last three months for a slow decline that content changes don’t explain, and pull a list of subscribers who haven’t opened anything in 90+ days to decide whether to re-engage or suppress them.
6. Platforms that handle this by default
Domain authentication and list-hygiene tooling shouldn’t require a developer to maintain by hand. Platforms built for ecommerce senders — Omnisend is one — walk you through SPF/DKIM/DMARC setup during onboarding and flag disengaged segments automatically, which removes most of the manual auditing above from your monthly task list.
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Deliverability isn’t glamorous, and it’s easy to assume it’s fine because nobody complained. It’s worth checking anyway — it’s the one problem that quietly caps the return on every other email you send.