The short answer
Find the app that sent the email, then compare its send time with the order time. Check that the cart and order use the same email address. Look for another app or a manual send. One late email does not tell you which step went wrong.
In this guide
Keep one clear example
A customer buys a necklace at lunch. Later, an email says the necklace is still in their cart. Start with that one case.
Save the email subject, the address it reached, the order number, and the times shown. Ask when the email appeared, but also check when the sender says it sent. An email can arrive later than its recorded send time.
Do not delete the flow or customer record before you can trace what happened.

- 01Sender
Find the exact email in a send log.
- 02Timeline
Compare the order with the recorded send.
- 03Fix
Change the cause you can confirm.
Which app actually sent it?
The shop name at the top of an email is not enough. Several apps may use the same name and logo.
Look for the matching subject and customer in each app's send history. Check Shopify Messaging, your old email app, signup-form emails, and any manual sends. Use the email overlap checker to list them.
If one app has no matching send, keep looking. You need evidence of the sender before changing its settings.
Do the cart and order match?
Compare the full email addresses on the cart and order. A person might browse with a work address and buy with a home address. Do not assume the sender joined those records.
Next, compare the items and times. Was this an old cart? Was the order placed before the app sent the message? Did the person start a second cart?
These are checks, not a diagnosis. Write down what matches and what differs. Do not merge records just to hide the problem.
Read the purchase check in the run
Shopify says its new checkout automation does not send when the shopper buys before the email is sent. For a Shopify send, open the matching run and delivery details.
If a custom flow sent it, inspect the purchase check and any wait that follows. Ask the app team which shopper and order data the check used. A result checked earlier may not describe the shopper at send time. Do not add more steps until you know what the current ones did.
Choose follow-up that uses shopper activity
myuser.ai chooses and sends follow-up using products, visits, carts, and orders. Its next message can change as shopper activity changes. You set your designs, offers, and channels, then activate sending.
That removes the need to build each marketing flow yourself. It does not control emails sent by other apps. Form follow-ups and manual sends also have their own controls. Review each sender when you switch tools. Read how its cart follow-up works before setup.
Sources & notes
Sources checked 2026-09-14. Product facts come from the links below; examples explain the steps. Read our research method and testing limits.
- Shopify checkout delivery details help.shopify.com
- myuser.ai automated follow-up myuser.ai
