60+ Cold Email Subject Lines: 10x Your Reply Rate [Updated 2021]

Cold email subject lines that will get your emails opened. Over 60 subject lines to help you get started!
March 10, 2021
Nafisa Nawal
Content Writer @ Outreachbin
60+ Cold Email Subject Lines: 10x Your Reply Rate [Updated 2021]
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Around the world, over 45% of all emails reach the spam box every day. Advertising and sales emails make up about 35% of all spam. Not to forget, improving the spam detection technology of email providers like Google made the job of marketers harder in today's age. (Looking to get out of spam automatically?)

Ideally, you may think that having good and engaging copies in the body wouldn't end your emails in the spam folders. But truth be told, today's spam filters may not be as intelligent. A spam filter doesn’t understand the contents of your emails as well as you or your recipient would.

Vitally, the filters use a series of signals to identify spam. However, most email providers don’t talk about these spam filter algorithms for obvious reasons. But experts reveal the following factors can significantly impact the eventual destination of your much-valued mails:

  • Open Rates: Whether your recipient opens your emails or not.
  • Replies: Whether your recipient replies to your emails or not.
  • Junk Folders: Whether your recipient moves your emails to junk folders or not.
  • Deletions: Whether your recipient deletes your emails or not.
  • Address Books: Whether your recipient adds your email addresses to their address book or not.

You may think many of these signals are out of your hands. But you know what? All these signals will work out well only if your recipient considers your emails relevant and important to them. And how do you make them believe that? First and foremost, you get them to read your emails. Use subject lines that reflect the essence and purpose of your emails.

Essentially, your subject lines should have a hook. It could be a benefit, offer, question, or call to action - anything that's relevant yet attention-grabbing.


The primary purpose of your subject line should be to make the recipient curious. It should encourage them to open the emails to know further. A good email subject line is creative, concise, and compelling. It insinuates value and benefits while still leaving a hook for the reader to open the mail.

Besides, follow mails are significantly crucial to ensuring smooth traction in your sales prospecting funnels. And just like any other mail, your follow mail should have a purpose. A subject line is what communicates that purpose. Some other follow mail subject line guidelines that lift off your open and reply rates are:

  • Your subject lines should be clear and comprehensible. It should be easy to understand for your readers. Do not go overboard with humorous nonsequiturs that don’t make sense at best.
  • Surveys reveal that 55% of recipients say they prefer marketing emails that include relevant products and offers. No doubt personalization is effective. Include the recipient’s name, their personal needs, and interests in the subject line. Someone once said it right -no two follow emails should look the same. You need to identify the challenges your prospects may be facing right now and offer solutions to just that. Content Manager of LeadFuze- Josh Slone says, “The more you personalize your subject line, the more benefits you can reap. Good contact data is key.”
  • Your subject lines must be timely, especially if you are a B2B marketer. Make sure you are aware of your prospects’ buying cycle. Your pitch could be perfect and yet fall on deaf ears for not being timely.
  • A good follow mail subject line should be creating a sense of urgency. It should encourage your recipients to open your messages immediately.
  • Your email’s subject lines also need to be adapted to the types of devices on which your recipients will read your messages. Some will read them from the comfort of their home's desktop computer; others may read them on their very own smartphones on a subway. Needless to say, a great email subject line should work wonders regardless of where your recipients maybe when reading the messages.


Let’s now look at a few questions you may want to ask yourself before crafting your follow mail subject lines:

  • What value are you offering?
  • Who are you offering it to?
  • Why are you doing so (for more open rates, reply rates, or conversion rates)?
  • Do you have any mutual connection with your recipients?
  • How familiar are your company/products/services to your recipients?
  • What kind of subject lines do the sales emails you delete usually have?
  • How do you plan to monitor and evaluate the success of your subject lines?


Some of the templates that you may seek to follow while articulating your subject lines are:

1. “Let’s talk about [topic/idea]!”

Why it works: It sparks curiosity. Who doesn't enjoy discussing their favorite subjects? That is what makes this subject line so enticing.

2. “A [better/smarter/faster] way to [reach a specific goal]”

Why it works: It identifies the recipient’s most pressing business pain points. It presents you as a giver – a bringer of solutions!

3. “Can I help you with [reaching a specific goal]?”

Why it works: It illustrates how you understand their ongoing situation and at the same time do not make any overt assumption about them needing you to solve it.

4. “Quick question regarding [project]”

Why it works: You are addressing your recipient, an expert who holds the answer to a key question. This makes them feel good.

5. “Hey [name], check this out.”

Why it works: It uses a familiar tone. Your readers will feel this strong urge to open the mail expecting to see someone they know.

6. “[Name], looking forward to seeing you at [event]!”

Why it works: This works magic when you know your prospect will be attending an event. It emphasizes the key purpose of events- that is, networking.

7. “Where do I even start?”

Why it works: It is abstract and vague. It piques your readers’ interests by making them want to find out more – by opening the email. But remember: the first line of your email should be much more specific.

8. “Are you ready to overcome [specific challenge]?”

Why it works: It depicts how you have done your share of research to make an informed guess of their pain points. You bet that they need the solution.

9. "Hey! Our [product/service] has your name all over it."

Why it works: It exudes enthusiasm and provokes interest. An added benefit is the humane "Hey.”

10. "A quick note from an aspiring [job role]"

Why it works: Not only the subject line itself is short and to the point, but it also insinuates the brevity of the email body.

11. " Looking to exchange ideas with a fellow [interests you both share]"

Why it works: It is friendly and conversational. It exudes reliability, and who doesn't like being on the same boat/page?

12. "A quick hello from [event] (and congrats on the [achievement]!"

Why it works: It connects the dots with a recent event your recipient may have attended. Besides, it illustrates admiration and appreciation of achievement- which most likely matters to them a lot.

13. “[Name], I need your advice.”

Why this works: It indicates that you value the prospect’s expertise and yet leaves your prospect curious as you do not specifically call out the topic. Dan Vanrenen, the Managing Director of Taskeater, recommends to “write a subject line that encourages them to respond and clearly signals your interest in what they have to say.”

14. “Would you like to catch up at [local establishment]?”

Why it works: It talks about a highly rated restaurant near your prospect's office. If you get lucky, you will hit the prospect’s favorite lunch spot.

15. “Request to connect”

Why it works: It promises the recipient an opportunity to expand his or her professional network. Of course, it works!

16. “Goodbye, [Name]”

Why it works: It prompts the reader to open the email to see just who exactly is saying goodbye. Using the prospect’s name adds more familiarity to the warm tone.

17. “You missed it.”

Why it works: It triggers your recipient's FOMO – the Fear of Missing Out on something. But what? The only way to figure out that is to open the email.

18. “Essential resources to help with [challenge]”

Why it works: It offers resources that are essentially useful and needed. Once you guess what your prospects need, the rest plays its own spells.

19. “Free to talk at [date]?”

Why it works: It creates a sense of urgency without being too alarming. Your emails are less likely to be unread if your prospects perceive a deadline.

20. “[Name] said we should connect.”

Why it works: References raise credibility. Associating your mail to your prospect’s colleagues or, better, the name of his or her superior is a perfect recipe for raising credibility. It depicts mutual connection and benefits showing that you’re someone worth talking to.

21. “Let’s cut to the chase.”

Why it works: It illustrates your respect for the prospect's time. It’s also short and includes suspense.

22. “Have you solved your [challenge] yet?”

Why it works: It is particularly effective when your prospect hasn’t yet solved the pain point you’re referring to. Even if you’re shooting in the dark, there’s a high chance they haven't.

23. “You’ll love this article, [name]!”

Why it works: It insinuates value. It shows that you have something that has the potential to solve their problems. At best, it will help improve your click-through rates.

24. “Next steps”

Why it works: It’s conversational. More often than not, your recipients will not be able to resist the urge to learn what those next steps are. According to Yesware, such subject lines can help your follow-up emails achieve up to a 70.5% open rate and a 49.6% reply rate.

25. “I forgot to mention…”

Why it works: It not only showcases you as a human to your recipients but also doesn’t come off as salesy. Such subject lines are best paired with useful resources and content that add value to your audience.

26. “Pleasure chatting with you, [prospect name]”

Why it works: It depicts sincerity and gratitude. Including the recipient’s name means added personalization and genuineness.

27. “Let’s take another look.”

Why it works: It insinuates that you have talked to your recipients before. Such subject lines must be paired with emails that offer new information or resources of value for your prospects.

Avoid overused subject lines such as “Checking in” or “Touching base. “Bottom line: Make sure you always have a reason for following up.

28. “Tuesday meeting at 10:00.”

Why it works: The mention of deadline and timing may mean added urgency. It exudes confidence, and it is more definite than a generic “sometime soon,” - which can be refused or avoided more easily. Such subject lines would expect an immediate response from your recipients, such as urgently checking on their calendar.

29. “Great meeting you today; I wanted to share something else.”

Why it works: It helps to show your recipients that you are on their radar. It stands out in their inbox since it talks about something relevant- your recent meeting with the recipient. As a cherry on top, the word share means you are offering some value to them that they need to reciprocate.

30. “Getting tired of salespeople who don’t give up?”

Why it works: It is candid. Such subject lines work best after 4-5 failed touchpoints. You can play along with messages of the body saying, “Me too. Meaning I pledge to stop contacting you if you aren’t interested. Just let me know if you need help with:

  • Pain point 1
  • Pain point 2
  • Pain point 3”

31. “Would anything change your mind?”

Why it works: It’s clear and concise enough to warrant opening. It helps keep the conversation going to learn more about your recipient’s interest in your next email.

32. “You are coming?”

Why it works: The brevity of the subject line ensures it stands out amongst all the other run-on sentence subject lines. It also has a personal tone with it while creating a sense of urgency.

33. "Question about [goal]"

Why it works: It sparked an interest. What's your question? Your email needs to be open for your recipients to find out.

34. "[Mutual connection] recommended I get in touch"

Why it works: No doubt the more your prospect trusts the referrer, the more trustworthy your email would be to them.

35. "Hi [name], [question]?"

Why it works: Questions will provoke your recipients to open and reply to your emails. Who doesn’t like helping others?

36. "Did you get what you were looking for?"

Why it works: Such subject lines are best suited for an inbound lead or a website visitor. It’s personal and friendly. Such emails offer help as you ask how you can be of service.

37. "Hoping to help"

Why it works: Gone are the days of Always Be Closing. Today is the era of Always Be Helping, according to the Entrepreneur and SMarketing pro-Dan Tyre.

38. "A [benefit] for [prospect's company]"

Why it works: Emails like “A new Finance strategy for XYZ Inc.” or “A savings of $50k for ABC Limited” are not only personalized to the recipient’s company name but also its needs.

39. "X tips/ideas for [pain point]"

Why it works: The increasing popularity of listicles means such subject lines will let your recipients know beforehand exactly what and HOW MANY benefits to expect!

40. "Idea for [topic the prospect cares about]"

Why it works: Useful and free resources? Sure, your recipients will love it! *click*

41. "10x [prospect's company]'s traction in 10 minutes"

Why it works: It adds numbers to benefits. Not only that! It gives you a timeline as well. Immediate gratification? Hell, yes.

42. "We have [insert fact] in common ..."

Why it works: Skim through your recipient's social media. You are sure to find something mutual and relevant!

43. "Nice to meet you, [Prospect]!"

Why it works: Such subject lines work best when your prospects downloaded content or visited your pricing webpage. It depicts how you appreciate their interest.

44. "Feeling [insert emotion]? Let me help."

Why it works: It helps you capitalize on the emotion overload that current events make your prospect feel. Then explain how your product or service can help them feel otherwise.

45. "You are not alone."

Why it works: Such subject lines hit home as you share stories of how others are facing similar challenges and are being helped by you/your service to overcome them.

46. "10 mins — [date]?"

Why it works: Brief and to the point. It will work wonders if you mirror this tone in your email body as well.

47. "A 3-step plan for your busy week."

Why it works: Who doesn't like relevant and actionable tips on their most pressing needs of time? Wait for it. Replies are flying your way.

48. "[Prospect], I thought you might like these blogs."

Why it works: Such subject lines are best suited when you want to check on your inactive or unresponsive prospects for signals of life.

49. "Here's that information I promised you."

Why it works: Make sure you end every communication with your prospect with a reason to follow up. This makes everything way easier. Voila!

50. "I'd love your feedback on that meeting."

Why it works: Following up after a demo or pitch meeting may mean you are more likely to stay top of the prospect's mind. Besides, responses may help you better tweak your approaches for next time.

51. “I had this idea since we last spoke”

Why it works: It enables your prospect to recall the last interaction and piques their interest in your idea, and to know more, they need to open your email.

52. “I thought about what you said.”

Why it works: It addresses a concern of your prospect that you show interest in. Sure, they will want to know more by opening your email.

53. “What would it take?”

Why it works: It has a rhetorical question full of suspense. They are sure to comply and open the mail.

54. “Here’s what I’ll do.”

Why it works: Leveraging the Law of Reciprocity offers and advice that even you would follow. That's interesting, hmm. But what exactly? This is what will prompt them to open the email.

55. "Do not open this email"

Why it works: Reverse psychology it is! Have you ever asked a toddler warm-up to not do something? Do they listen? Heck, no!

56. "Should I stay or should I go?"

Why it works: It is a great way to check on your recipient's continued interest if you haven't heard from them in a while. At best, it helps you wrap a sales relationship professionally.

57. "Know this about [topic of interest]?"

Why it works: A wonderful subject line that keeps the conversation flowing. If they want to know more, they are surefire going to click!

58. "If you change your mind about availing our [your product/service]"

Why it works: It helps break up the radio silence of the unresponsive ones.

59. “I love everything in this email!”

Why it works: It works best when it is paired with a body that pokes fun like, "OK, so my boss said that, but..."

60. "Am I assuming correctly?"

Why it works: It sounds human and seeks empathy. Say something on the line of assuming that this isn't a priority for your prospect's company at the moment. Well, is your assumption right? They got to respond to let you know that.

61. "Time for a quick touch base?"

Why it works: It is low-pressure. It is conversational. But make sure you have some time-based call to action at the mail body for a more timely response.

Overall, your follow mail subject lines should not come off as overly sales-driven or off-putting.

Bottom line: Use a natural and candid tone. Besides, do not forget:

  • According to the SuperOffice, 56% of recipients open their email on mobile. Hence, it’s important to have brief subject lines since the lengthier ones will get cut off in small-screen devices. Ideally, your subject line should be five to six words.
  • Avoid capitalizing every word in your subject lines. This makes you more of a human and less of a salesy API.
  • Make sure you meet the expectations and fulfill whatever your subject line promises in your mail body. Unscrupulous promises or “clickbait” will do nothing but lose business.


Breaking news! The articulation of your follow mail subject lines is not the only thing that affects the success of your subject lines. Make sure you tweak some other necessary components that entail your follow mails to get the best of results as follows:

  • Divide your email list: Segregate your audience into segments by need, interests, or some other criteria. Bottom line: Not all emails you send should look the same.
  • Use an active reply-to address: Do not send emails from email addresses like “[email protected].” This does nothing but insinuates to your audience that communication is one-way only.
  • Warm-up your emails: Your emails should seem as human and credible as possible to not land in spam. Optimizing your mail account for deliverability is crucial. For instance, buying and setting up G Suite for your domain will offer better deliverability than an @gmail.com account. Ideally, you should wait it out for at least 12 weeks after opening your email account for outbound campaigns.

Time to use your account as any standard user would. Sign up for newsletters and mailing lists. Sign into social media. Send customized and differentiated mails to some friends. Make them reply to you and then reply to their replies to create conversation threads. Another surefire trick is to send emails to addresses that are set up on domains from various hosts.

Most importantly, do not forget to test your automated cold email campaign for 20 email addresses you know are real. Time to get grips with the automated cold emailing tool while your email account is getting its warm-up. Make sure your mailbox activity is properly personalized. Do not send too many emails and ruin your sender's reputation. Make sure the emails you send are spaced out and run the campaign over a longer period.

  • Personalize your email address: Remember to create an authentic identity. Add a profile picture. Next, add an email signature with your Name, Job title, Company name, Address, Phone number, Email address, and Website. Make sure you use your real details for these. While you may be reluctant to do so, such nuances go a long way to ensure your emails get read.
  • Optimize the snippet: Use a snippet that is the short length of text that appears on the right side of the subject line. It is what gives your recipients a preview of the email content. Avoid any unsubscribe link, whitelist request, or housekeeping jargon while trying to keep the most thought-provoking hook here.

Ideally, the above-mentioned tips will mean higher-than-average open rates for your emails. But how to check?


Generally, your instincts can go a long way in determining which follow mail subject line works best for you. But there is an added benefit of an objective perspective. One of the best ways to check the effectiveness of your subject lines is A/B testing.

All you need to do is pick and shortlist a few subject lines that are likely to convert. Then test them on different target segments while monitoring the email open, click, and conversion rates. Tweak and adapt your campaigns over time. Running experiments with your email tactics are great tools to get upright insights on how to improve your outcomes. Before diving in, make sure you:

  • Figure out what your objective is- may be open and response rates for starters.
  • Set quantifiable and realistic goals for those metrics.
  • Identify how many variations and for how long you want to test each subject line. Make sure you prepare sets of the subject line, snippet, and email while sending each set to around 100 to 1,000 emails.
  • Forget not to challenge your current techniques periodically.
  • Pay special attention to follow-ups from recipients.

In today’s age, persistence is key when sending emails to your prospects. Studies show that only 18% of people respond to the first email sent, 13% to the fourth, and around 27% to the sixth one. The success of your follow emails depends a lot on how effectively you manage to get past the gatekeeper. Your audience is receiving an avalanche of email every day while many of them end up in spam filters by the gatekeeper- your recipients’ email providers.

According to the American author and entrepreneur Keith Ferrazzi, “The currency of real networking is not greed but generosity.” It unlocks the attention of your recipients and builds your bridges with them. Following up promptly while not being too aggressive means you or your company/products/services are still fresh in the recipient's memory.

Therefore, navigating your way past the noise of your recipient’s inbox is no easy feat. Reaching out and following up hundreds of prospects manually can get on your neck. Hence, tools like Outreachbin will work wonders while personalizing your emails and sending them in bulk in exactly the sequence you prefer!


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OutreachBin helps you with both warmup and cold emails. It enhances your sender’s reputation. Not only that, it helps you run and evaluate successful email campaigns for the best of outcomes. Besides, the tool also automatically generates prospect lists based on your email campaigns, their open rates, and replies.

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