Onboarding Nudge
Send this when a new user signs up but has not finished the first setup step. It shows a progress bar for step 1 of 3, names the single task, and gives one button with a time estimate. Rename the step to the action that makes your product useful, link the button straight to it, and stop the email once the user completes it.
Loops
Send it only to people who are stuck
Track the first setup step as an event or a contact property your app updates. Add a timer after signup, then a branch or audience filter so users who already finished the step skip the email. Repeat the pattern for steps 2 and 3, or use the Onboarding Drip template to show the whole first week at once.