AI wrote your email subject. What does the inbox preview say?
An invented cinema notice: subject, ‘Friday's screening is cancelled.’ Preview, ‘Refunds are automatic; you don't need to contact us.’ That second line could spare someone a worried email. ‘An important update awaits’ would only give them another thing to open. If AI is helping write the notice, I'd ask for those two fields together, using the confirmed refund policy—not ten increasingly intriguing subject lines. Mailchimp's existing guide says that without custom preview text, email clients pull from the start of the message, which can mean ‘View in browser’ or HTML code. It also says the visible space is limited, so put the useful detail first. In Mailchimp, a regular email's Subject section has separate Subject and Preview Text fields. I'd send a test to my own phone and read the inbox row before opening it. That's a check I'd suggest, not a rendering test I've run; one inbox won't prove how every email app displays it. For a cancellation notice, I'd happily lose an open if the person already understood what happened and knew they didn't have another job to do.
Comments
I'd give the writing assistant a separate instruction about what must stay out of the inbox row. An appointment reminder can state the date without naming the treatment; a payment notice needn't put the amount owed beside the subject. Those are invented examples, but they change the brief: useful before opening should not mean private details before opening. For sensitive messages, I'd approve the subject and preview together for that reason, even if the longer version is clearer. The recipient can choose when to open the email. They have less choice about who happens to glimpse their inbox.
I would ask the person handling refunds to read that preview before it goes out. In the cinema example, ‘you don't need to contact us’ needs an exception route in the email for anyone whose booking isn't covered by the automatic refund. I'd have the assistant draft from the refund team's confirmed instructions, including when the money should arrive and who to contact after that date. Otherwise the box office may spend the next week explaining a promise it never made. A short inbox line can spare a call; it shouldn't leave the person with the unusual booking wondering whether they're allowed to ask for help.
I'd keep the AI subject-line test away from ‘winner by open rate’ for notices like this. Mailchimp warns that Apple Mail Privacy Protection can preload tracking pixels without a person opening the email, making open-based A/B results unreliable. But even a perfectly measured open would not tell you whether the cancellation notice helped. I'd ask a few readers what they think happens next, and check whether confused refund enquiries follow the send. Neither is a complete measure on its own. A subject that makes people anxious enough to open immediately should not beat a clear one just because the dashboard prefers it.
I'd repeat the inbox check after the last rewrite, not just after the first draft. Imagine the cinema changes its notice from ‘all Friday screenings’ to one particular showing, but the saved subject still sounds like the whole evening is cancelled. Mailchimp puts the subject and preview in separate fields; I'd read those beside the final message before sending. Ask the AI to flag contradictions across the three, then check them yourself. A corrected paragraph inside the email won't reassure the person who sees the old subject and starts rearranging their evening. That's an editing check I'd suggest, not a mismatch I've observed in Mailchimp.