Cold email is an email equivalent of cold calling – sending an email without prior contact with a recipient. Usually, the main intent of a cold email is promoting a product or a service or starting a business conversation. Cold emailing is not an easy way to communicate, mostly because you don’t have any relationship with the recipient yet, making it difficult to get your email read without a proper strategy for writing a subject line for a cold email.

Subject Lines

Unfortunately, sometimes cold emails are considered spam by spam filters, but with a proper strategy, there is a way around that. If you’re trying to prevent your cold email ending up in the spam folder, you should ensure that your domain name, server IP and email address have a good reputation.

Email addresses are appointed with good or bad reputation depending – if a lot of spam has been sent from the address you are using to send your cold emails, it’s almost a guarantee that the email will end up in the spam folder. Email list validation services like Byteplant will help you ensure that your email list is valid and up-to-date, maximizing your email marketing budget and keeping your sender reputation intact.

The second and probably the most important step is to get the recipient to read your email, and that’s where subject lines come into the game. A crucial element of sending cold emails is choosing the best subject line for a cold email. By coming up with a great, catching, appropriate subject line for your cold email, you will get the recipient to open, read, and respond to the email.

So what are the most important factors in choosing an ideal cold email subject line? Your subject line should stand out from the masses of promotional and business emails in the inbox. It should be interesting as well as informative, but not too informative enticing the recipient to open and read the entire email. By employing psychological principles and playing the card of basic human curiosity, you can increase email opens significantly.

Some ideas for cold email subject lines

Here are some ideas for cold email subject lines that will help you get the reader’s attention and hopefully encourage them to open and read your email:

Scarcity and urgency:

People are very susceptible to fear of scarcity and sense of urgency, and by employing that element, you will make the recipient open your email. Use words that give the recipient a feeling that he may miss out on something if he doesn’t open your email, for example: “Great offer – Expires soon!”, “Offer valid for limited time only!” and using words like “urgent”, “important” or “breaking”.

Open-ended subject lines:

By leaving your subject line open-ended, you can leave the recipient curious, urging to satisfy that curiosity only when he or she opens and reads the email. Curiosity is the key element here – you can ask a question in the subject line and give the answer in the email or say something interesting or unusual that will leave your reader hanging on the edge of his seat until he opens your email. Example: “Did you hear about the biggest mystery of the 21st century? It’s…”


If you share a business partner or an acquaintance with the person you’re trying to contact through a cold email, it can be a great idea to mention that person’s name in the subject of your cold email. Depending on the relationship of the recipient with the person you are mentioning, the chances of your email being opened can increase significantly. For example: “I got your contact from…”


Do not send generic emails, think about who the recipient is, what are his interests and how can you connect them with your intents. Mention his or her name in the subject and make them feel like you put time and effort into researching who they are and what they want. By spending only a couple of minutes to check out your recipient’s social networks, you can learn a lot about his interests and incorporate that into your email subject line which will automatically increase the chances of your email being opened. Example: “Cindy, we picked this product just for you!”

Avoid misleading subject lines:

When composing subject lines for cold emails, make them relevant to the email body. In case the subject line doesn’t have anything to do with the content of the email, your recipient may feel misled and mark the message as spam. Even though misleading cold email subject lines won’t impact the probability of the email being opened, they will undermine the recipient’s trust in your company in the future.

Stand out from the masses:

By using lowercase only in the cold email subject line, your email will visually stand out from all the others in the inbox so it will get noticed right away. Another way to stand out from the hundreds of emails your contact probably has in their inbox is humor – don’t be afraid to start off with a joke. If your subject line can make the recipient laugh, it’s a guaranteed open.


Great deals are a sure way to get your email opened. If you are trying to sell something – a product or a service, mention a discount or a special offer in the subject line. However, it’s important to keep it realistic – don’t offer discounts that are too high or implausible in any way. Examples: “SALE!”, “%% off our best-sellers”, “Buy 1, get 1 free”.

Offer a solution to their problem:

“Feeling stressed or overworked? Here’s how we can help.” is just one of many examples of the problem – solution tactic. In today’s modern world, everyone’s stressed and overworked, and mentioning that fact in the cold email subject as well as claiming your product or service can help the recipient overcome this is a good way to get your email opened.


No matter which approach you choose in coming up with the best subject lines for cold emails, remember to be original and creative and to differentiate yourself from other companies who send thousands of cold emails daily in hope to boost their sales. Also, don’t forget that the majority of users open their emails on their smartphones or tablets, so make sure your subject line is compatible with mobile devices.