Your open rate looks fine because you cannot see the messages that never arrived.
Email revenue has been drifting down for months and every explanation you have tried does not fit.
4 min read
Email deliverability failures do not announce themselves. Nothing bounces, no error appears, and your platform reports messages as delivered. They simply arrive in a folder nobody opens, and the only symptom is revenue slowly declining for reasons that look like fatigue.
The requirements tightened materially. Gmail, Yahoo and Microsoft now enforce authentication and complaint thresholds on anyone sending at meaningful volume, and enforcement escalated from warnings to actual rejections. Compliant senders are reported to average around 89% inbox placement; non-compliant senders see a large share of their mail routed to spam.
This is what has to be in place, and how to check whether it is.
The requirements, plainly
0.3%
Spam complaint ceiling above which bulk mail is systematically filtered; 0.1% is the working target
Chronos Agency sender requirements guide
5,000/day
Volume at which bulk sender requirements apply in full — a threshold most growing D2C brands cross
Red Sift bulk email sender requirements
- SPF, DKIM and DMARC must all be set up and aligned. Not one of them. All three.
- DMARC must be published. Starting at monitoring is acceptable, but the expectation is progression toward quarantine or reject.
- One-click unsubscribe must work, and must actually remove the person.
- Spam complaints must stay below 0.3%. Treat 0.1% as your real ceiling, because 0.3% is where filtering becomes systematic rather than where problems begin.
- You must send from a domain you control, with valid forward and reverse records.
Diagnosing a deliverability problem
Deliverability problems and content problems look identical in your reporting. These distinguish them.
| Pattern | What it points to |
|---|---|
| Open rate falling at one mailbox provider but not others | Deliverability, at that provider specifically |
| Open rate falling across all providers evenly | Content, timing or list fatigue |
| Recent subscribers opening, older ones not | Reputation damage, or a list that needs cleaning |
| Sudden drop on a specific date | An authentication change, a domain change, or a sending platform change |
| Transactional mail fine, marketing mail poor | Reputation on the marketing subdomain |
Send yourself a test to accounts at each major mailbox provider and look at where it lands. This is cruder than any tool and it answers the question in five minutes.
List hygiene, which is most of the job
Mailbox providers infer whether people want your mail from how they behave. Sending to people who never engage is the fastest way to teach them the answer is no.
- Stop mailing subscribers who have not opened anything in a defined period. Six months is a common line; the exact number matters less than having one.
- Never buy or import a list. It will not just underperform — it will damage the reputation of the domain your good mail depends on.
- Use confirmed opt-in where you can, particularly for lists gathered at events or through giveaways.
- Remove hard bounces immediately and repeated soft bounces promptly.
- Watch the complaint rate per campaign, not just overall. One badly targeted send can move a quarterly average.
- Warm a new domain or platform gradually. Moving your whole volume to a fresh domain on day one is the classic way to start from zero reputation and stay there.
The ecommerce specifics
Two decisions matter more for stores than for most senders.
Separate your transactional and marketing sending
Order confirmations and shipping updates must arrive. If they share a reputation with your promotional sending, a bad campaign can put your delivery notifications in spam — which generates support tickets, not just lost revenue. Use separate subdomains.
Treat a purchase as consent to a relationship, not to everything
A customer who bought expects order updates. They did not necessarily ask for three campaigns a week. Conflating the two is the most common cause of complaint rates rising in ecommerce lists, and the complaint rate is the metric that governs whether any of it arrives.
Common questions
What are the current bulk email sender requirements?
SPF, DKIM and DMARC all set up and aligned, a published DMARC record, working one-click unsubscribe, and spam complaints below 0.3%. These apply in full to senders above roughly 5,000 messages a day.
What spam complaint rate is safe?
Below 0.3% is the enforcement ceiling, but 0.1% is the working target. 0.3% is where filtering becomes systematic, not where the problem starts.
Why is my email going to spam when nothing bounced?
Delivery and inbox placement are different things. A message can be accepted and then filed in spam, which your platform reports as delivered. Test to accounts at each major mailbox provider and look at where it actually lands.
Should transactional and marketing email use the same domain?
No. Use separate subdomains, so a poorly received campaign cannot put order confirmations and shipping notifications into spam.
How often should I clean my email list?
Continuously for bounces, and on a defined schedule for unengaged subscribers — six months without an open is a common cutoff. Sending to people who never engage is what teaches mailbox providers to filter you.
How Glimmio handles this
Glimmio sends lifecycle email through your own connected mailbox, so the sending identity and its reputation stay yours rather than being pooled with other businesses.
Consent and suppression are enforced on every send from the same workspace that holds your order data, which is what keeps a marketing send from reaching someone who only ever agreed to order updates.
- Manual approval by default — nothing runs unattended
- New campaigns and ads are always created paused
- 7-day recovery window on eligible changes
- 48 permissions across 13 roles, scoped per client account
Go deeper on this
The product pages and setup guides that cover what this article describes.
Searches this answers
- email deliverability ecommerce 2026
- gmail yahoo bulk sender requirements
- spf dkim dmarc shopify store
- email going to spam ecommerce
- spam complaint rate threshold
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