The best subject line for a follow-up email is usually the one you already used: reply in the same thread, so it shows as “Re: [original subject]” and they see the history. When you need a new subject line, keep it short, name the topic or the ask, and skip “Just following up” on its own. Below are 50+ examples by situation. And if remembering to follow up is the real problem, Mixmax, a lightweight outreach tool inside Gmail, sends the follow-up you wrote if they don’t reply, and stops the moment they do.
Follow-up subject lines by situation
When they emailed you first, then went quiet
- Re: [their original subject]
- Your question about [topic]
- Quote for [project]
- Times to talk this week
- Still looking for help with [topic]?
- One more option for [topic]
- Did this answer your question?
When you’re adding something new
- Info I promised
- Forgot to mention…
- Before you decide…
- Two ideas for [topic]
- Happy to do [task]
- A quick example
- Answer to your question
- Here’s what I’ll do instead
After a meeting or call
- Next steps
- Notes from our call
- 3 takeaways from [day]
- What we agreed
- Thought about what you said
- The [document] I mentioned
- More examples?
- Any questions?
- Good chat, next step?
- Action items from [day]
After you sent a quote or proposal
- Re: [project] proposal
- Questions about the quote?
- Can we make the [date] start?
- A smaller option for [project]
- Holding [date] for you
When they asked you to check back later
- You said to reach out in [month]
- Checking back on [topic], as promised
- [Month] plans for [topic]
- Is now a better time?
- Ready for [project]?
After an event or introduction
- Great to meet at [event]
- Continuing our chat from [event]
- The [thing] I mentioned at [event]
- [Mutual contact] suggested we talk
When you need a yes or no
- Yes or no on [topic]?
- Should I hold [date]?
- Quick decision on [topic]
- Still on for [date]?
The last follow-up
- Closing the loop on [topic]
- Should I stop?
- Change of plans?
- Last note on [topic]
- No worries if not
A little lighter (use with people you know)
- Is it something I typed?
- All good?
- Did this get buried?
How to write a follow-up subject line
- Reply in the same thread when you can. “Re: [original subject]” is the most familiar subject line there is.
- Keep it short. Long subject lines get cut off, especially on phones.
- Name the topic or the ask. “Quote for your kitchen” beats “Following up.”
- Match the email. The subject line should say what’s inside. No bait.
- Sound like a person. Write it the way you’d write to a colleague you like.
- Use the preview text. The first line of your email shows next to the subject in most inboxes, so make it count: “Following up on the quote, I can start on the 14th.”
Subject lines to avoid
| Avoid | Why | Try instead |
|---|---|---|
| ”Just following up” | Says nothing about the topic | ”Your question about [topic]" |
| "Checking in” | Makes them remember why you wrote | ”Next steps for [project]" |
| "Why haven’t you replied?” | Guilt rarely gets a reply | ”Did this get buried?" |
| "Please reply” / “Sorry to bother you” | Sounds desperate | ”Quick question about [topic]" |
| "URGENT” (when it isn’t) | Breaks trust fast | Name the real deadline: “Before Friday’s deadline” |
Send the follow-up without having to remember it
A good subject line only works if the follow-up actually goes out. With Mixmax in Gmail:
- Sign up with Google (free to start, no credit card).
- Write your email, then write the follow-up and pick when it sends, for example three days later.
- Send. If they reply, the follow-up never goes out. If they don’t, it sends as a reply in the same thread, so it keeps your original subject line.
Prefer to write it later? Set “remind me if no reply” and Mixmax reminds you only if they haven’t answered. More in how to automatically follow up in Gmail.
Frequently asked questions
Should I change the subject line when I follow up?
Usually not. Reply in the same thread so the subject reads “Re: [original subject]” and they see the whole conversation. Use a new subject line only when you’re starting a new topic.
Should I write “follow up” in the subject line?
Not on its own. “Follow up” doesn’t say what the email is about. Name the topic instead: “Follow-up on the kitchen quote” is fine; “Following up” isn’t.
How long should a follow-up subject line be?
Short enough to read in full on a phone, usually a handful of words.
What’s a good subject line for a follow-up after no response?
Reply in the original thread, or name the topic and the ask: “Your question about [topic]” or “Still on for [date]?”
What’s a good subject line for the last follow-up?
Something calm and clear: “Closing the loop on [topic]” or “Should I stop?”
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