Follow Up Email Subject Lines: Examples

What should a follow up email subject say when nobody replied?

A follow-up to an unanswered cold email can do one of two things in the subject line. It can show that the message belongs to something already in the reader's inbox, or it can name a specific new reason to open. A subject that does neither just reads as "still waiting". The examples below are written out in full. Swap in your own details where you see braces.

• Re: {original subject}
• {First name}, one detail I left out
• A different angle on {problem you raised}
• {Company}'s {process} — a question I should have asked
• Before your {quarter/event} planning starts

Use "Re:" only when the email really is sent as a reply in the same thread. "One detail I left out" only works if the body adds that detail. If it just repeats the first email, the subject has promised something you didn't deliver. Save "a different angle" for the third touch, when you actually switch arguments, say from cost to risk. The timing hook only fits if you know their planning cycle. Whatever you choose, put the distinctive word first. RFC 5322 recommends header lines of no more than 78 characters, but mobile inboxes cut subjects off well before that.

Should a follow-up keep the original subject with "Re:"?

Usually, yes, if the follow-up is a real reply. Mail clients build a thread from the In-Reply-To and References headers defined in RFC 5322, section 3.6.4. Each one points back to the Message-ID of the earlier email. Gmail also looks at the subject: change it and Gmail opens a new conversation, even if the headers point back. When the headers and the "Re: {original subject}" line match, the reader sees your first email right under the follow-up, so they don't have to go searching for the context.

Here's what doesn't work. A "Re:" or "Fwd:" on a first-touch email that replies to nothing claims a conversation that never happened. CAN-SPAM, 15 U.S.C. 7704(a)(2), bans subject headings likely to mislead the recipient about the content or subject matter of the message, and a fake reply prefix is exactly that kind of misstatement. Start a new subject when the thread has drifted to another topic, or when your new message makes a point the old subject line no longer describes.

What's a good email example for a follow-up after a call or meeting?

After a live conversation, the subject can be plain and specific, because the reader already knows who you are. Name the meeting or the thing you promised to send. Don't try to sound clever.

• Notes from our call on {date}
• The {document} I promised on {day}
• {Company} + {your company}: next steps from Tuesday
• Answer to your question about {topic}
• Pricing breakdown you asked for, {first name}

Send "Notes from our call" when several people attended and someone needs a record they can forward. "The {document} I promised" ties the email to a commitment you made, and it only works if the attachment or link is actually in the email. "Next steps" fits once a decision has been agreed. "Answer to your question" is the best choice when a single open question is holding things up, because the reader can match it to that question straight away. Don't send any of these after a call that never happened: inventing a meeting in the subject line misleads the reader in the same way a fake "Re:" does.

What should a sales follow up email include besides the subject?

A sales follow up email needs four parts. Start with one line that links it to the earlier message. Add one new thing the first email didn't have. Make one clear ask. Finish with a way to opt out. If it's a reply in the same thread, the quoted original handles the context, so you don't need to sum it up again. The new thing could be a fact about their company, an answer to a likely objection, or a short video. Whatever it is, the subject should name it.

When the new thing is a video, here's how EmailFlow OS handles the sending. You record one video and upload it. You connect your own Brevo account and sending domain, and you import your prospect list into EmailFlow OS. EmailFlow OS then creates a personalised version of that one recording for each recipient, not one per company. Each version goes out from your own inbox, through your Brevo account and your domain. That means the From address, the DKIM signature and the sender reputation stay yours, and there's no shared platform sender behind any of it. It also means a subject like "Recorded this for {first name}" accurately describes what's in the email.

Sales follow up email sample: what does a complete one look like?

Here's a full sample for the second touch after an unanswered first email, with a personalised video. Replace everything in braces.

Subject: Recorded this for {first name} at {company}. Body: Hi {first name}, I wrote last week about {problem}. Instead of another paragraph, I've recorded a short walkthrough of how {specific process} could look on your side. The video's below. If it's relevant, does {day} at {time} work for a 20-minute call? If it isn't, just reply "no" and I won't follow up again. {Your name}, {title}, {company}, {postal address}.

Each line has a reason to be there. The subject says exactly what the email contains. The opening line recalls the first email in a single sentence. The ask is one specific time slot rather than "let me know". The "reply no" line and your postal address cover what CAN-SPAM requires: a working opt-out and a valid physical postal address. If you send in Germany, UWG §7 is stricter about unsolicited advertising email, so check your consent basis before the first touch, not at the follow-up. And don't use this sample word for word. Text that's identical across many senders is easy for filters to fingerprint.

How do you write a breakup follow-up subject line?

The breakup email is your last message in a sequence. Its subject should say plainly that this is the end, without guilt-tripping the reader.

• Closing the loop on {topic}
• Last note from me, {first name}
• Should I stop writing about {topic}?
• Wrong person for {topic} at {company}?
• Leaving this here for later

"Closing the loop" is neutral and works in almost any sequence. "Should I stop writing?" gets an answer either way, and a "yes" is useful too: honour it and take the address off every list you run. "Wrong person?" fits when you're unsure you've reached the decision-maker. Some signals mean you shouldn't send a breakup at all. A hard bounce such as 5.1.1 (user unknown) means the mailbox doesn't exist, so sending again only adds to your bounce count. An out-of-office reply means you should wait, not close the loop.

Questions people ask

? How long should a follow up email subject be?

There's no single published cut-off, because every mail client truncates at a different width. RFC 5322 recommends header lines of no more than 78 characters and sets a hard limit of 998. In practice, put the word that makes the email unique first, such as the name, the topic or the document, so it survives when a phone screen cuts the line short.

? Is "Following up" a good subject line on its own?

Not really. "Following up" says the email is connected to something, but not what that something is. If the email is a real reply, "Re: {original subject}" does the same job and also keeps it threaded through the In-Reply-To and References headers. If the email isn't a reply, name the new thing it contains, for example "Notes from our call on {date}".

? Can I put "Re:" on a cold email that isn't a reply?

You shouldn't. CAN-SPAM, 15 U.S.C. 7704(a)(2), prohibits subject headings likely to mislead the recipient about the message's content or subject matter. A "Re:" on a first-touch email suggests a conversation that never happened. Mail clients also won't thread it, because it has no In-Reply-To header pointing to an earlier Message-ID.

? Can I use emojis in a follow-up subject line?

Technically, yes. Non-ASCII characters in headers are encoded under RFC 2047, and most current clients display them. How they look varies between clients and operating systems, though, and some older systems show the raw encoded string. In B2B follow-ups, an emoji tells the reader nothing about the email's content, so the specific word you'd have put in that spot usually serves you better.