Abandoned Cart flow skipping ALL recipients with "Email Syntax Error" — valid addresses affected

--- Additional details:

• Issue started: approximately September 25, 2026
• Smart Sending: OFF
• Consent at checkout: "Email me with news and offers" checkbox — checked by all affected users
• Clean addresses being skipped: onyeka.adegoke@gmail.com (standard Gmail, no special characters)
• Shopify integration was disconnected and reconnected September 29 — issue persists
• All 17+ skipped recipients show identical reason: "Email Syntax Error"
• Flow trigger: Checkout Started (Shopify native integration)
• No flow-level filters set

[Attach screenshot of Recipient Activity showing "Skipped: Email Syntax Error (17)"]

onyeka.adegoke@gmail.com moved from waiting to skipped now

Best guess without seeing the actual email is that there is an issue with one of your placeholders or with the dynamic table in your email. 

Nothing to do with Smart sending or the shopify integration but with the email itself. Just check your email for any dynamic content ({{ first_name }}) or the the table in there. Maybe delete it from that email and check the preview if you can see the event data there or if there is a message saying something with “message is showing without tags or variable” => That means there is still the syntax error. If you see the event data reverse what you deleted and check that element. Sometimes is a simple as using the wrong ‘’ when trying to set a default for a dynamic variable.