Write the welcome email new signups actually open

Product: {{what it does, in one sentence}}. Who just signed up: {{segment}}. What they were trying to accomplish when they signed up: {{the job}}. The one action that predicts they'll stick: {{activation action}}.

Write the first email. It must do exactly one thing: get them to take that action. Not tour the product, not introduce the founder, not list features.

Structure: subject line under 40 characters, no preheader repeating the subject, an opening line that references what they just did, the single action with a plain-language reason it's worth the two minutes, one link, and a real sign-off from a person.

Under 120 words. No emoji, no 'welcome aboard', no 'we're excited', no bulleted feature list.

Then give me: three subject line variants of clearly different types, and the follow-up to send in 48 hours only to people who did not take the action — different angle, not a reminder.