What are effective re-engagement email subject line hooks for an app?

Hi! For inactive app users, the re-engagement subject lines that most consistently work are the ones that (1) remind them of the value they already wanted, (2) reduce effort to restart, and (3) feel like a personal check-in—not a promotion. The best “angle” depends on why people went quiet (forgot, got stuck, didn’t see value yet, or churned), so below are proven hooks and when to use each, plus opening lines that match.

Proven re-engagement subject line angles (and when to use each)

1) “Pick up where you left off” (best for 7–30 days inactive)

Why it works: It assumes good intent and lowers friction—no guilt, just continuation.
Subject ideas:

• “Ready to pick up where you left off?”
• “Your next step is waiting”
• “Continue from where you stopped”
• “A quick way to get back on track”
  Opening hook ideas:
• “Want to jump back in? Here’s the fastest way to continue from your last step.”
• “You were partway through—tap once to pick up where you left off.”

2) “What’s new (that matters to you)” (best when you have real updates; 14–90 days)

Why it works: “New features” only works if it’s clearly relevant; make it benefit-led.
Subject ideas:

• “A few updates you might actually care about”
• “New: [benefit] is now easier”
• “We made [pain point] simpler”
• “You asked, we improved [thing]”
  Opening hook ideas:
• “Since you last opened the app, we’ve improved the part that used to take the most time: [benefit].”
• “Quick update: you can now [job-to-be-done] in fewer steps.”

3) “Personal progress / recap” (best if you can personalize; 7–60 days)

Why it works: Specific beats generic. Even a light recap can reignite motivation.
Subject ideas:

• “A quick recap of your progress”
• “You’re closer than you think”
• “Here’s what you’ve already done”
• “Your week/month in [App]”
  Opening hook ideas:
• “You’ve already [did X]. The next best step is [Y] (it takes about a minute).”
• “Here’s a quick snapshot—and one suggestion to keep momentum.”

4) “You might be stuck—here’s help” (best for users who didn’t complete onboarding)

Why it works: Helpful, non-salesy, and addresses the real reason people drop off: confusion.
Subject ideas:

• “Need a hand getting started?”
• “Stuck on setup? This fixes it”
• “1-minute setup checklist”
• “Common first-step questions (answered)”
  Opening hook ideas:
• “If setup felt confusing, you’re not alone—here’s the simplest path to get value fast.”
• “Most people get unstuck by doing this one thing first…”

5) “Make it easy: one clear outcome” (best for busy users; any inactivity window)

Why it works: It promises a single, concrete win instead of “come back to the app.”
Subject ideas:

• “Do this in 2 minutes”
• “One quick step for [result]”
• “A simple way to [benefit] today”
• “Try this shortcut”
  Opening hook ideas:
• “If you only have a minute, do this: [single action] → [result].”
• “Here’s the fastest way to get [benefit] without starting over.”

6) “Social proof / popular path” (best when personalization is limited; 30–120 days)

Why it works: It removes decision fatigue: “start here.” Keep it subtle (no hype).
Subject ideas:

• “Most people start here”
• “The #1 way people use [App]”
• “A popular workflow you can copy”
• “Want a simple template?”
  Opening hook ideas:
• “If you’re not sure where to begin, this is the most common starting point.”
• “Here’s a ready-to-use template that gets results fast.”

7) “Preference check / reset expectations” (best for 60–180 days, pre-sunset)

Why it works: It respects inboxes and can improve deliverability by prompting engagement or a clean opt-down.
Subject ideas:

• “Still want emails from us?”
• “Should we keep these coming?”
• “Choose what you want to hear about”
• “Update your preferences?”
  Opening hook ideas:
• “No pressure—do you want updates like this, or should we pause?”
• “Pick what’s useful (or opt out) in one click.”

8) “We’ll pause your account / data note” (only if true; final attempt)

Why it works: A truthful, time-bound reason can trigger action—but don’t fake urgency.
Subject ideas:

• “Do you want us to keep your account active?”
• “Before we pause your updates”
• “Last check-in—want to stay subscribed?”
  Opening hook ideas:
• “We haven’t seen you in a while. If you still want to use [App], here’s the easiest way back in.”
• “If not, you can also tell us to stop emailing—either way is totally fine.”

A few quick rules to keep it helpful (not spammy)

• Lead with their goal, not your app. (“Finish your plan” beats “We miss you.”)
• Avoid guilt/trip lines. (“We noticed you haven’t…” can feel creepy; “Ready when you are” is softer.)
• Use one clear CTA. Re-engagement emails work better when there’s a single next step.
• Match the hook to the inactivity window. Early = continuation/help. Later = recap/new value/preferences.
• If you offer an incentive, frame it as a nudge, not a bribe. Use sparingly and only for users who didn’t respond to value-based emails.

If you tell me what your app helps users do (and roughly how long they’ve been inactive—7 days vs 90+), I can tailor 15–20 subject lines and opening hooks that match your exact use case and tone.