Did you know the cold email response rate is 5.1%, with the average open rate being 27.7%? Cold emailing, where you reach out to potential clients who've never heard of your product or service before, can feel like a gamble.

But is it possible to engage a client right from the first letter, or is it just a myth?

Read the article and learn how to write cold emails to boost email deliverability and look at examples of cold emails.

How to Improve Email Deliverability in Cold Outreach

Before we get started with the nitty gritty of how to improve email deliverability cold outreach, let start from the basics.

Introduction to Cold Email Deliverability

Cold email deliverability is the foundation of any successful cold email campaign. Simply put, it’s the ability of your emails to reach the recipient’s primary inbox instead of being flagged as spam or ending up in the spam folder. Inbox placements—whether your emails land in the primary inbox, promotions, or spam—are a key measure of deliverability success. When you send a cold email, email service providers like Gmail, Outlook, and Yahoo use advanced filters and algorithms to decide whether your message is legitimate or should be filtered out. If your emails consistently land in the spam, your chances of connecting with prospects drop dramatically.

Why does this matter? Because even the most compelling cold email won’t generate results if it never reaches the recipient’s primary inbox. High cold email deliverability ensures your message is seen, read, and acted upon, making it a critical factor in the success of your cold email outreach. Inbox providers treat senders differently based on recipient engagement and sender reputation, which directly impacts deliverability. In this section, we’ll break down why deliverability is so important and introduce the key factors that affect whether your cold emails make it to the inbox or get lost in the spam folder.

Understanding Email Deliverability

Email deliverability is more than just hitting “send” and hoping for the best. It’s a complex process influenced by your technical setup, sender reputation, and the quality of your email content. Email service providers use sophisticated algorithms to evaluate every cold email you send, looking at factors like your domain reputation, the authentication protocols you use, and your sending habits.

Key elements that affect cold email deliverability include:

Domain Reputation

This is a score that email service providers assign to your sending domain based on your sending history, engagement rates, and spam complaints. A positive domain reputation increases the likelihood that your emails will reach the inbox.

Sender Policy Framework (SPF)

SPF is an authentication protocol that verifies your emails are sent from authorized servers. Setting up SPF helps prevent your emails from being spoofed and reduces the risk of being flagged by spam filters.

DomainKeys Identified Mail (DKIM)

DKIM adds a digital signature to your emails, allowing email providers to verify that the message hasn’t been altered in transit. This builds trust with inbox providers and improves deliverability.

Domain Message Authentication Reporting and Conformance (DMARC)

DMARC works alongside SPF and DKIM to give you more control over how your emails are handled if they fail authentication checks. It also provides valuable feedback on your email performance.

Mail servers and email servers play a crucial role in processing and authenticating emails, directly impacting deliverability. Additionally, internet service providers (ISPs) implement filtering and security measures that determine whether your emails are delivered to the inbox or sent to spam.

Understanding these factors—and how they interact—will help you build a strong foundation for your cold email campaigns and maximize your chances of landing in the recipient’s inbox.

Technical Setup for High Deliverability

A robust technical setup is essential for ensuring your cold emails reach their intended destination. The reputation of your company's domain and sender domain are critical factors for deliverability, as ISPs and filters closely monitor these to determine whether to trust your emails. Start by choosing a reputable email service provider that supports advanced authentication protocols and offers reliable infrastructure. Next, configure your email accounts and email clients to align with best practices for deliverability.

Here’s a step-by-step guide to setting up your technical infrastructure:

1. Configure DNS Records: Set up your domain’s DNS records to include SPF, DKIM, and DMARC. These records authenticate your emails and signal to spam filters that your messages are legitimate.
2. Set Up SPF and DKIM: Work with your email service provider to generate and publish SPF and DKIM records. This process typically involves adding specific TXT records to your domain’s DNS settings.
3. Implement DMARC: Create a DMARC policy to monitor and control how your emails are handled if they fail authentication. DMARC also provides reporting, so you can track your email deliverability score and spot potential issues.
4. Use Dedicated Email Accounts: Avoid sending cold emails from your main company domain or personal email accounts. Instead, set up dedicated email accounts specifically for cold outreach to protect your primary domain’s reputation. If you are using a new domain for outreach, make sure to warm it up gradually by sending low volumes at first to build sender reputation and avoid triggering spam filters.
5. Check Sending IP Address and SMTP Server: Ensure your sending IP address and SMTP server have good reputations and are properly configured. A poor reputation or misconfigured SMTP server can negatively impact your sender domain’s deliverability and inbox placement.
6. Test Your Setup: Use email deliverability test tools like Mail Tester to check your configuration and identify any issues that could affect deliverability.

By following these steps and maintaining a clean technical setup, you’ll improve deliverability, reduce the risk of your emails being flagged by spam filters, and increase the chances that your cold emails land in your prospects’ inboxes.

Working with Email Providers

Each email provider—whether it’s Gmail, Outlook, Yahoo, or another service—has its own unique set of rules and filters that determine where your email lands. Understanding these differences is key to improving deliverability and ensuring your cold emails reach the recipient’s inbox.

Here are some tips for working with different email providers:

• Gmail: Gmail’s spam filters are particularly strict. To improve deliverability, avoid using spammy words, keep your sending volume consistent, and always include an unsubscribe link. Personalization and plain text emails often perform better with Gmail’s algorithms.
• Outlook: Outlook tends to flag emails with excessive links or attachments. Keep your emails concise, limit the use of images, and ensure your SPF, DKIM, and DMARC records are correctly set up.
• Yahoo: Yahoo’s filters focus heavily on sender reputation and engagement rates. Encourage recipients to reply or move your emails to their primary inbox to build a positive sender reputation.

No matter which email providers you’re targeting, always monitor your inbox placement and adjust your strategy based on feedback. Regularly check your email deliverability score and use cold emailing software that offers insights into how your emails are performing across different providers. By adapting to the unique requirements of each provider, you’ll maximize your chances of reaching your audience.

Multiple Domains and Email Deliverability

Using multiple domains is a smart strategy for boosting email deliverability and protecting your primary domain’s reputation. By setting up secondary sending domains, you can isolate your main company domain from potential deliverability issues that may arise during cold email campaigns. When using new domains for cold outreach, it's important to warm them up gradually by slowly increasing email volume to establish a positive reputation and avoid spam filters.

Here’s how multiple domains can help:

• Risk Isolation: If a secondary sending domain encounters deliverability problems or gets flagged by spam filters, your primary domain remains unaffected. This protects your main business communications and brand reputation.
• Improved Inbox Placement: Rotating between multiple sending domains can help you avoid triggering spam filters and increase the chances that your emails land in the recipient’s primary inbox.
• Scalability: Using multiple domains allows you to scale your cold outreach without overloading a single domain, which can negatively impact sender reputation and email deliverability.

To get started, register secondary domains that are similar to your primary domain, set up proper DNS records (SPF, DKIM, DMARC), and use them exclusively for cold email outreach. For new domains, follow proper domain warming procedures by gradually ramping up sending volume and avoiding sending to inactive or unengaged contacts. Monitor the performance of each sending domain and adjust your strategy as needed to avoid spam and maintain high inbox placement.

By leveraging multiple domains, you can run more effective cold email campaigns, reduce the risk of deliverability issues, and ensure your messages consistently reach your prospects’ inboxes.

Authenticating Emails with SPF, DKIM, and DMARC

One of the most effective ways to improve email deliverability and avoid the dreaded spam folder is by properly authenticating your emails. Authentication protocols like Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, and Conformance (DMARC) are essential tools in your cold email outreach arsenal.

SPF works by verifying that the IP address sending your emails is authorized to do so by your domain. This helps prevent spoofing and signals to spam filters that your messages are legitimate. DKIM adds another layer of security by attaching a digital signature to each email, allowing inbox providers to confirm that the message really comes from your domain and hasn’t been tampered with in transit. DMARC ties everything together, letting you specify which authentication protocols to use and instructing email servers on what to do if an email fails these checks. It also provides valuable message authentication reporting, so you can monitor how your emails are being handled.

Implementing SPF, DKIM, and DMARC not only protects your brand from phishing and spoofing but also builds a stronger sender reputation. A good sender reputation means your emails are more likely to land in the recipient’s primary inbox, rather than being filtered out as spam. Plus, with DMARC’s based message authentication reporting, you can quickly spot and resolve any authentication issues that might affect your cold email deliverability.

By taking the time to set up these authentication protocols, you’ll reduce spam complaints, improve your domain’s standing with email service providers, and give your cold email campaigns the best possible chance of reaching your prospects’ inboxes.

Managing Email Lists and Unsubscribe Links

Keeping your email lists clean and making it easy for recipients to opt out are crucial steps for maintaining a positive sender reputation and ensuring your marketing emails don’t end up in spam . Regularly managing your email lists means removing invalid addresses, bounced emails, and anyone who has unsubscribed or filed spam complaints. This not only helps you avoid deliverability issues but also ensures you’re sending emails to people who actually want to hear from you.

Including a clear and visible unsubscribe link in every email is not just a best practice—it’s a requirement under most anti-spam laws. Unsubscribe links make it simple for recipients to opt out of future emails, reducing the likelihood of spam complaints that can damage your sender reputation. When someone clicks your unsubscribe link, honor their request promptly and remove them from your list to avoid sending unwanted future emails.

By actively managing your email lists and making it easy for recipients to unsubscribe, you’ll minimize spam complaints, protect your sender reputation, and improve the overall deliverability of your cold email campaigns. This approach helps ensure your sending emails reach engaged prospects and land in the primary inbox, where they’re most likely to be seen and acted upon.

Testing and Monitoring Email Deliverability

Even with the best practices in place, it’s essential to regularly test and monitor your email deliverability to ensure your cold emails are reaching the recipient’s inbox. Email deliverability test tools are designed to help you identify potential issues with your sender reputation, email authentication, and content before they impact your campaigns.

By running deliverability tests, you can check if your emails are being flagged by spam filters, verify that your SPF, DKIM, and DMARC records are working correctly, and see how your emails perform across different inbox providers. These tools also provide insights into your inbox placement, showing whether your emails are landing in the primary inbox, promotions tab, or spam folder.

Monitoring your email deliverability allows you to catch problems early and make adjustments to your cold email strategy. Whether it’s tweaking your email content, updating authentication protocols, or cleaning your list, regular testing helps you maintain a strong sender reputation and maximize the effectiveness of your cold email outreach.

Using Inbox Placement Tools

Inbox placement tools are invaluable for anyone serious about improving cold email deliverability. These tools go beyond basic deliverability checks by providing detailed reports on where your emails actually land—whether it’s the primary inbox, spam , or another tab. With insights from inbox placement tools like GlockApps, MailboxValidator, and ClearSlide, you can see exactly how your email campaigns are performing across different email providers.

By analyzing inbox placement, you can quickly identify if your emails are being filtered into spam or blocked altogether. This information allows you to make targeted improvements to your campaigns, such as adjusting your sending patterns, refining your content, or addressing authentication issues. Consistently monitoring inbox placement not only helps you avoid the spam folder but also strengthens your sender reputation and increases the likelihood that your emails will be seen in the recipient’s primary inbox.

Using these tools as part of your deliverability checklist ensures your cold email campaigns are always optimized for the best possible results.

4 Key Steps to Write Cold Emails to Improve Email Deliverability

Let's discuss 4 main basic steps.

1. Identify Your Target Audience

Sending messages to uninterested people is pointless. Before writing a cold email for a mailing list, define the target audience and find out the meaningful criteria:

• Users’ geolocation
• Industry in which they are building a career
• Age, gender
• Number of employees
• Corporation’s products
• Favors, etc.

Identifying a target audience is necessary to write only effective words and target only the people who need them. This is also a foundational step for successful lead generation in cold outreach.

Prepare Email Database

Several options for gathering a database exist:

It is crucial to collect only valid and verified email addresses for cold outreach to ensure high deliverability and engagement. Sending to invalid email addresses can result in bounced emails, which harm your sender reputation and reduce campaign effectiveness. Catch all domains can make it difficult to verify the validity of email addresses and may increase the risk of bounced emails. Additionally, purchased or scraped lists may contain spam traps, which can severely impact deliverability and cause your emails to be marked as spam.

Purchase

Usually, purchased databases contain invalid addresses and incorrect data; often, these lists also include spam traps, which can damage your sender reputation and deliverability. These databases are critically spammed. You will spend money, but the mailing will not give a good result. Focus on safe and effective ways to collect email databases.

Use Tools

This option is better than the previous one, but it has flaws. Parsing programs (as such programs are called) can find invalid emails.

Using this option, check the collected list with the help of email validation services. It will help you effectively mail to active users and attract attention to your product/service.

Manual search

It requires a lot of time. You can outsource the task: only financial investments and patience will be required. It takes at least 24 hours to manually gather a list of 50 people.

Again, there is no guarantee that the emails are up to date. Perform a validity check. Otherwise, you risk blowing your budget.

Don't Overload the First Email

Writing service Essay Tigers advises: “Don’t add links, attachments, PDFs, flashy animations!” They distract from the text part and make spam filters distrust you. Including too many links in your email can trigger spam filters and reduce engagement, so limit the number of links to improve deliverability. Maintaining a good text to HTML ratio is also important—plain text emails often appear more natural and are less likely to be flagged as spam. If you apply this advice, you’ll end up in Spam.

When warming up a new email account or domain, it’s best to start by sending only a few emails to gradually build sender reputation and avoid spam filters.

All in due time! In the future, add graphic elements and attachments. The purpose of the first touch is to connect with your audience, not to scare them with an abundance of files.

Here is the difference between a cold email and spam:

Capacity and brevity

People don't want to read a canvas from an unknown sender. Keep it short. Imagine yourself in the place of the consumer. It will help to look at the email through the eyes of the addressee. If interested in the offer - he will specify the details.

Personalization

Address by name, address exclusively to the target audience and indicate where you got their emails from. Use humor and a polite conversational style.

Don't be intrusive

Take care of the comfort of the recipients. Do not try to immediately sell a product or service. Work on building an image. The second is to send a letter of continued cooperation; well-timed follow ups are essential for maintaining engagement and improving deliverability. The effectiveness of the subsequent campaign depends on the public’s reaction to the first e-mail.

Openness

Specify the real mail and the sender’s name. Specifying the sender's domain in your emails helps build trust with recipients and improves deliverability. Anonymous messages from mysterious users increase distrust and the risk of being sent to Gmail's Spam. It’s easy to get there, but getting out and restoring your reputation is not the easiest task.

Clarity

The topic should be clear. Study the list of spam words and avoid them in the body and subject line of the email. Sending spam emails or irrelevant content increases the risk of being filtered out by spam filters. Using spam trigger words in the email body can increase your spam score and trigger spam filters, reducing your chances of reaching the inbox. Always send relevant emails tailored to the recipient, and focus on providing relevant content to improve engagement and deliverability. Tools are available to analyze your email content for common spam triggers and help you optimize your email body for better deliverability.

Remember, your task is to avoid landing in spam box when you are doing cold mailing. Then, you will definitely increasethe click-through rate in cold emailing.

2. B2B Cold Mailing: Optimal Size for Cold Emails

Before writing the email itself, let’s decide what size it should be and how many emails to send. As for the volume, the email should not be too long.

Sending emails to invalid or full mailboxes can result in soft bounces, which are temporary delivery failures caused by issues like a full recipient's inbox or server downtime. Soft bounces negatively impact your sender reputation and email deliverability.

Managing your email volume and gradually increasing the number of emails you send is crucial for maintaining deliverability. It’s better to send campaigns in smaller batches rather than mass emails, as sending too many emails at once can trigger spam filters. Always send emails in a way that mimics natural communication patterns to avoid deliverability issues.

Otherwise, the recipient will simply not read it to the end. But at the same time, the volume should be sufficient to tell about your company and describe your offer. The optimal size is 1000 characters (about half a page). The maximum is 1500 characters.

Break the text into logical paragraphs. Make long enumerations in labeled lists. Thus, the text for cold mailing will not look like a continuous mess and is difficult to read.

The number of follow-up emails is 2-3. If you haven’t received a reply to the first one, send an email with a reminder. If the second one remains unanswered, it is not worth sending more and disturbing the recipient. In rare cases, send a third follow-up email a week later.

Right Subject Line - Half of Cold Email Success

Despite the fact that the subject line is just one sentence, it determines whether a person will open the email or not. Therefore, clearly but concisely formulate your offer in the subject line. Also, take a few tips to heart:

• Don't use the words “reminder,” “free,” “percentage off,” or “help” as they reduce email open rates.
• Personalize the subject line, as it will increase the open rate by 26%.

It's best if the subject line is no longer than 30 characters. Although the maximum theme size for desktop devices is 70 characters, Apple devices only display 30 characters. If you want it to fully display on all devices, then don't make it longer than that.

Structure of a Cold Email That Sells

For many people, the task of writing a text becomes impossible. You open the Word - and nothing comes to mind. So, where do you start, and how do you write an effective cold email?

Everything will become much easier and clearer if you know the classic structure and just follow it. So, an email to a potential client has the following elements:

• Greeting
• About yourself or the company
• Offer (what you are offering to the person)
• Call to action
• Signature

As you can see, there is nothing complicated here. You can easily write your first cold email!

3. Call to Action - Don't Forget About It!

Without a clear call to action, your email is meaningless.

The target action could be a purchase or other type of cooperation or a call/meeting to discuss details. Don't go to the other extreme either, oversaturating the text with calls to action.

In a cold email, there can be only one.Recently, an effective trick with a call to action in the form of a question has become very popular. Examples of wording:

• When is it convenient for you to meet/call to discuss the details of cooperation?
• What will you say?
• Do you want to know more?

But you should be careful with such wording and use it only if you are sure that the person exactly falls under your target audience and your offer is really favorable. Otherwise, your self-confidence can cause, on the contrary, a negative reaction.Cold Email Design: Do You Need a Visual Part?

In cold emails, the design does not play a decisive role. On the contrary, a sales email template that is too overloaded may not have the desired effect.

Besides, the purpose of such an email is to create a feeling of personal correspondence, not a mass sales mailing. Therefore, make the design as simple as possible:

• Don't add a lot of pictures. First of all, emails with more pictures than text are more likely to go straight to spam. Secondly, some people cut off emails that are too large in size. For example, Gmail often compresses pictures in emails larger than 102 kb. Therefore, everything may not look the way you intended it to look to the recipient.
• Do not insert GIFs. First, they take a long time to load and may not display correctly at all. And secondly, they simply irritate people who receive an email from your company for the first time.

The only thing you can (and even should) add is a photo of the sender in the email signature.

In general, experiments with visuals are allowed and even necessary when sending emails to regular customers who have subscribed to your newsletter. After all, they will be bored of receiving the same text emails.

But it is better to make a standard cold email template with the simplest possible design (or even without it at all, just text and nothing extra).A/B

4. Refining Your Cold Email Strategy

Understanding the difference between email delivery and deliverability is crucial: email delivery means your emails are accepted by the recipient’s mail server, while deliverability refers to whether those emails actually reach the inbox and are seen by the user. If your emails are not properly optimized, they may end up in the recipient's spam, reducing the likelihood of engagement.

Optimizing your cold email strategy directly affects email deliverability, helping ensure your messages land in the inbox rather than the spam.

Including clear unsubscribe links and respecting recipient preferences reduces spam complaints and improves your sender reputation.

Cold emailing lives on, with continuous optimization. To get better results, testing different parts of your email campaigns is necessary.

This is where A/B testing and spintax come into play:

A/B testing

Try to experiment with different subject lines, CTAs, and copies of emails to find out what really works best for your target audience. For instance, test whether a question-based subject line works better than a value-driven one or whether a shorter call-to-action increases clicks.

Smartlead's AI Auto Adjust A/B Testing feature allows you to optimize your email outreach and drive more meetings for your business.

By running tests on email variations, you can refine your approach and identify the best-performing strategies.Before diving into A/B testing, make sure you have completed the following steps:

1. Set up your email account in the Smartlead app with SPF, DKIM, DMARC, and MX records to ensure proper email authentication.
2. Warm up your inbox for at least two weeks to prevent deliverability issues.

Now, let's walk through the steps to perform A/B testing with Smartlead.

‍Step 1: Add a New Campaign: In the Smartlead app, click on the “Add Campaign” button to create a new campaign.

Step 2: Import Your Leads: Upload your lead list by either importing a CSV file or syncing with your CRM.

Step 3: Create Your First Variant: Compose your initial email and save it as your first variant. Then, click on the “Add Variant” button to create additional versions of the email you want to test.

For example, if you're testing 5 variants, your setup would look like this:

Step 4: Choose Your A/B Testing MethodSmartlead offers three ways to distribute your variants. Here's how to use each method:

Manual Equal Distribution

With this method, Smartlead will equally distribute your variants across all leads automatically.

How to Set Up:

• Click on the “A/B Configuration” button.
• In the “A/B Testing Settings” popup, leave the default settings as they are: Manual Distribution and Split the variant percentage equally
• Click “Save Manual Distribution,” and you're done! Smartlead will handle the rest.

2. Manual Distribution with Variant Percentage Allocation

This option lets you manually adjust the percentage of leads that receive each variant, allowing you to control the distribution.‍

How to Set Up:

• Click on the “A/B Configuration” button after adding your variants.
• In the “A/B Testing Settings” popup, select Manual Distribution.
• Choose “Split the variant percentage equally.”
• Adjust the percentage for each variant as needed. Keep in mind that each variant needs at least 10% of your total pool for reliable results.
• Click “Save Manual Distribution” to finalize your settings.

3. AI Percentage Distribution

With AI Percentage Distribution, Smartlead automatically optimizes which variant performs best based on the metrics you choose, such as open rate, reply rate, or click rate.

How to Set Up:

• Click on the “A/B Configuration” button after adding your variants.
• In the “A/B Testing Settings” popup, select AI Percentage Distribution.
• Use the slider to choose the variation distribution percentage, from 10% to 80%.
• Under “Choose Winning Metrics,” select the metric that matters most for your campaign (e.g., reply rate, open rate, etc.).
• Click “Save AI Percentage Distribution,” and Smartlead will automatically optimize the campaign based on the chosen metrics.

Step 5: Launch Your Campaign

After selecting your A/B testing method and configuring your variants, you're ready to launch your campaign. Keep an eye on performance metrics like reply rates, open rates, and click rates to determine which variant is performing best.

Step 6: Monitor and Optimize

Once your campaign is live, monitor the performance metrics closely. Use the insights gained from A/B testing to refine future campaigns, making data-driven decisions that boost engagement and drive more meetings.

Spintax

When you send cold emails, email service providers (ESPs) monitor patterns. Sending the exact same email to 1000 people often raises flags, making it look like a “mass” email.

Using dedicated cold email software, rather than general marketing tools, helps improve deliverability and avoid spam filters because it is specifically designed for sending outreach emails.

However, using slightly different versions of the same email can help trick ESPs into thinking you’re engaging in one-on-one conversations rather than sending bulk messages. This is where Spintax comes in.

‍Spintax in Smartlead allows you to create variations of your message with minimal effort.

This way, even though much of your email stays the same, small differences in the copy increase deliverability while helping your emails appear more personalized.

Conclusion

Sending mass cold emails makes it hard for one to keep up with efficiency yet be personal. Smartlead can help you automate essential components of email campaigns.

Crafting effective cold emails is both an art and a science. By focusing on personalization, clear subject lines, and compelling content, you can engage your recipients while boosting deliverability rates.

Remember to test your emails, maintain a clean contact list, and adhere to email marketing regulations to build trust and improve performance.

The key is to balance professionalism with a touch of humanity, ensuring your message resonates without overwhelming the recipient.

With persistence and attention to detail, cold emails can become a powerful tool to expand your network, generate leads, and drive business growth. Start optimizing your cold email strategy today!