Aeralis is winding down and its free tools have been retired. Thanks for using them.
Free Sales Email Subject Line Generator
Get 5 subject lines for sales emails — outreach, follow-ups, breakups, and post-demo emails. Built for SDRs, AEs, and founder-led sales teams.
25+ sales email subject lines, by stage
Swipe file of proven sales subject lines across the full pipeline — from first touch to final follow-up.
Initial outreach
- {firstName}, worth 15 min?
- Helping {company} with [outcome]
- A question about {company}'s [workflow]
- Re: your [launch/announcement]
- Is [owner role] still the right person?
Follow-up (prospect went silent)
- Did this get buried?
- Bumping this up
- Still relevant?
- Worth another look?
- One last check-in
Break-up / final follow-up
- Closing the loop
- Should I stop following up?
- Final follow-up: [topic]
- Let me take this off your plate
- No worries if not a fit
After a demo / meeting
- Next steps from our call
- Your {company} evaluation plan
- Recap + next step
- Following up on [what you discussed]
- Quick summary from today
Reactivating old leads
- Any new thoughts on [topic]?
- Checking in after [last event]
- Are you still on [problem]?
- Revisiting our conversation
- {company} + [us]: still worth a chat?
Sales email subject line best practices
Match subject to pipeline stage
Cold outreach needs curiosity and specificity. Follow-ups need brevity and low pressure. Post-demo emails need clarity on next steps. One subject pattern does not fit all.
Use "Re:" honestly
Fake "Re:" prefixes (where there was no prior conversation) trigger spam filters and destroy trust when the recipient notices. Use "Re:" only when replying to a real thread.
Give prospects an exit
Subject lines like "Closing the loop" or "No worries if not a fit" consistently outperform aggressive follow-ups. People respond to relief of pressure — not more of it.
Track opens per stage
Your cold open rate and follow-up open rate should be measured separately. Follow-ups typically open at 30–50% higher rates than cold emails. If they're lower, your follow-up subject lines are failing.
Need more than a free tool?
Like sales email subject line generator? The Aeralis Gmail add-on does this and more, right inside your inbox.
Free tier includes 8 emails/month. No credit card required.
Frequently Asked Questions
Common questions about our sales email subject line generator
What subject lines work for sales follow-ups?
The best sales follow-up subject lines are short, low-pressure, and keep the conversation going. "Re:" prefixes work (most clients automatically add them anyway). "Any thoughts?", "Bumping this up", and "Still relevant?" consistently outperform aggressive subjects.
How many sales follow-ups should I send?
Industry data (Yesware, Salesloft) shows 5–8 follow-ups for cold prospects is the sweet spot — higher converts but diminishing returns after 8. For warm leads (replied once, then went dark), 2–3 follow-ups usually surface a yes or a clean "no."
Should sales emails mention the prospect's company in the subject?
Yes for cold outreach. No for follow-ups. In cold subjects, company names and specific details lift opens. In follow-ups, the recipient already knows the context — keep it conversational and short.
What's the best subject line for a sales email that went unanswered?
Proven unopened-email subject patterns: "Did this get buried?", "Re: our conversation", "Worth another look?", "Bumping this up — final follow-up", "Closing the loop on [topic]". Keep it humble, short, and escape-route-friendly.
What sales email subject lines trigger spam filters?
Avoid: "LIMITED TIME," "ACT NOW," "GUARANTEED," "FREE TRIAL," "URGENT," "DON'T MISS OUT," dollar signs, and ALL CAPS. Also avoid "Quick question" x 5 emails in a row — sequence pattern detection flags it.
Is this sales email subject line generator free?
Yes, completely free. Generate up to 10 sets of 5 sales subject lines per hour. No signup, no credit card, no CRM integration required.
See also: cold email subject lines · cold email personalizer
More Free Email Tools
Other free tools you might find useful