The Ultimate Guide to Growing Your Email Program

Here's how to turn any modest email list into a bountiful source of engagement, conversions, and revenue.

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In the ever-evolving landscape of digital communication, email remains a resilient and flourishing medium. It’s a channel where businesses can nurture relationships, cultivate brand loyalty, and reap the rewards of a thriving subscriber base. But much like a garden, your email marketing efforts require careful planning, constant care, and the right nurturing techniques to bear fruit.

Ready to discover on your email green thumb? In this guide, we’ll explore the strategies and tactics that can help you turn a modest email list into a bountiful source of engagement, conversions, and revenue. So put on your gardening overalls and join us as we embark on a journey to cultivate email success from seed to full bloom.

Chapter 2 : Why is email important?

Whether you’re planting your very first email seeds or tending to an already flourishing garden of subscribers, you’ve likely realized email’s incredible potential. While email can be influential in driving clicks and conversions for your business, it can do so much more. 

Upon digging deeper, here are the many ways a strong email program can help your business: 

  • Drive traffic to your website
  • Grow your customer base
  • Increase the lifetime value of your customers
  • Strengthen relationships with your recipients
  • Collect feedback on your products and services
  • Drive registrations and attendance to your company’s virtual and in-person events
  • Communicate with your audiences
  • Increase brand awareness
  • Learn more about your recipients
  • Serve users personalized content
  • Own your contact lists
  • Build credibility and trust 

If you’re ready to enjoy the beautiful blooms of a successful email program, keep reading to learn how. 

Chapter 3 : Gather your tools

Before breaking ground, a gardener must come prepared with their tools of the trade: gloves, a spade, a watering can, shears, and more. Luckily for you, email marketers benefit from having all these tools in one place with the right email service provider. By choosing a solution like Twilio SendGrid’s Email API, you can build and monitor your email solution on a trusted foundation—with technical and strategic support when you need it most. 

With Twilio SendGrid, you’ll benefit from to: 

  1. Proven email deliverability on our globally distributed, cloud-based architecture.
  2. A purpose-built mail transfer agent (MTA) that delivers over 135 billion emails/mo for brands like, Shopify, Klaviyo, and more.
  3. Time-saving features like fast troubleshooting, secure account management, and intuitive UI for data analysis.

In just minutes, you can sign up for Twilio SendGrid’s Email API and start helping your developers, marketers, and business leaders collaborate seamlessly and start sending messages your prospects and customers love. 

Learn more about Twilio SendGrid’s Email API now → 

Next, you’ll need to ensure you have the right nutrients in your soil to promote the healthy growth of your email program. Without a strong foundation to pull from, your email campaigns can wither or worse — fail to reach your recipient’s inboxes. 

To ensure your email program is set up for success from the ground up, follow these best practices: 

1. Set up your IP address(es)

An IP address is a unique number block that identifies a device using the internet protocol (IP) to communicate over a certain network. It affects your sender reputation and how internet service providers (ISPs) judge your sending patterns, so it’s a very important part of scaling any email program. 

Depending on your needs, you’ll need to choose from the two kinds of IP addresses

  • A shared IP: This IP address is shared with other senders, meaning their sending behavior impacts your reputation and deliverability. If you share with bad actors your email program can suffer, but on the other hand, you can also reap the benefits of an IP address with a high reputation if you’re a low volume sender.
  • A dedicated IP: This means you are the sole sender using this IP address, giving you the utmost control over your reputation and deliverability.

Most ESPs provide the option to send email on a shared IP pool or a dedicated IP address, so they can help you choose what’s best for your business’ needs and monthly sending volume. Should you choose the latter, getting a dedicated IP can be pricey, but Twilio SendGrid focuses on affordability. 

All Twilio SendGrid Pro Plan users get a dedicated IP address, so you can own your reputation, automate your IP warmup, and easily manage additional IP addresses as needed. This plan also includes additional benefits for your program, like email validation, subuser management, and single sign-on, and more. Learn more on our pricing page or get started for free by creating an account now


Consider using use separate IPs for sending transactional and marketing email

If you send both transactional and marketing email, it’s a good idea to keep them separate by using two different IP addresses. By using unique IP addresses for transactional and marketing emails, your business can have peace of mind knowing your vital transactional messages’ deliverability won’t be affected by the reputation or engagement of your marketing emails.

2. Complete sender authentication

Before you can start firing off emails, you need to help ISPs determine you are who you say you are. Sender/domain authentication indicates to ISPs that you’re a legitimate sender and that your chosen email service provider has your permission to send emails on your behalf. Once an ISP knows you’re a legitimate sender, they’re more likely to ensure your messages reach your recipients.

There are four ways to authenticate your email messages: 

  1. DomainKeys Identified Mail (DKIM) adds a digital signature to your emails so inbox providers can verify that your domain sent the message and determine that you’re responsible for the content of the message. It can help ISPs detect forged email sender addresses, also called email spoofing, which is a common phishing technique so the ISPs can prevent bad actors from using your email address.
  2. Sender Policy Framework (SPF) identifies the mail servers that are allowed to send emails from a particular domain. While DKIM allows ISPs to verify that the content sent is what the original sender intended, SPF allows administrators to specify which hosts are allowed to send mail from a given domain by creating a specific SPF record in the Domain Name System (DNS).

    Neither SPF or DKIM fully secure an email. Each is missing an important piece. SPF is missing message verification and DKIM is missing a way to verify where the message is coming from. Both are needed to be a secure email sender. Learn more here.
  3. Domain Based Message Authentication, Reporting, and Conformance (DMARC) is one of the best things you can do to protect your domain from spoofing and phishing attacks. Should an email fail to be authenticated using SPF or DKIM, your company can instruct the receiving server to either do nothing, move the message to spam, or completely block the message altogether.
  4. Brand Indicators for Message Identification (BIMI) adds your company’s logo to your emails so your messages can be quickly and easily identified by recipients. In order to be eligible for BIMI, your brand must first have DMARC implemented with either a quarantine or reject policy and a strong domain reputation. Since BIMI can’t be implemented by just any sender, having BIMI can really give you a head start in the inbox competition. 

3. Warm up your IP

Like plants, ISPs love consistency, especially when it comes to sending volume. Sending 100 emails on Monday and 100,000 on Tuesday gives mixed signals. Was that 100,000-email campaign just a massive spam send? ISPs probably think so. Send too many emails at one time and ISPs will likely throttle your emails, which can delay delivery time, frustrate your users, and likely cause a decrease in engagement.

Consistent sending level shows ISPs that you’re conducting business as usual and, more importantly, that you’re not a phisher or spammer. If you do end up sending high volumes of email, make sure you “warm up” your IP, or build up your sending amount gradually.

Looking to work your way up to sending millions of emails a month?


Chapter 5: Grow your email list

You won’t see the fruits of your labor on day-one. Sustainable growth takes time, patience, and a little bit of love. In order to scale your email program successfully, you’ll also need to plant some seeds and grow your very own email subscriber list

Not sure where to start? Here are a few best practices to help grow your email list: 

  • Leverage on-site forms or pop ups: Include sign-up forms on your webpages or in your website footer to make it easy for your users to sign up. Some companies even use pop-ups to catch potential subscribers’ attention! 
  • Offer incentives to join: Offering incentives like discounts, free shipping, freebies, or exclusive content can help you entice people to join your email list.
  • Include an email list opt-in checkbox on content forms: If you have forms on your website for quizzes, webinars, or content downloads, consider including an optional checkbox to allow users to quickly and easily opt-in to your email list while they’re taking different actions around your site. 
  • Encourage sign ups through social media: Regularly remind your social media followers to join your email list to stay up-to-date on your latest company news, product releases, and more. 
  • Run contests and giveaways: Contests can be a great way to incentivize people to sign up for your emails. You can even partner with a few brands that target similar audiences to your own in order to increase your contest’s reach!
  • Cross pollinate your list with SMS: Already have a well-established SMS subscriber list? Send a text message encouraging them to sign up for your email list too, this can help you reach people who while familiar with your brand may not be on your email list just yet. Check out Using SMS and Email to Engage Your Customers in 2023 for more best practices around how to use email and SMS together. 
  • Use paid ads: If you have the budget, consider using paid advertising to reach more people and encourage email signups. You can even target specific demographics and job titles to ensure your brand gets in front of the right individuals.

Keep all or some of these strategies running in the background of your email efforts and you’ll be sure to amass a growing list of qualified recipients in no time. 


Do NOT purchase email lists.

While it can be tempting to buy subscribers and have a large email following from day-one, do not purchase email lists. Purchased email addresses have not opted-in to receive your messages and probably don’t want to hear from you. Not only will you not see the engagement you’d want, but you’ll also experience high bounce rates, spam complaints, and unsubscribes, which will damage your sender reputation and lead to deliverability issues.


Use a double opt-in.

A double opt-in requires users to proactively confirm their subscription before they receive messages from your brand. This helps you prevent invalid email addresses from making it onto your list and ensures everyone who signs up actually wants to receive your emails.

Looking for more tips on how to grow your email list?


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Once you’ve cultivated your digital garden of subscribers and built your email infrastructure, it’s time to sow the seeds of engagement and create an email program that catches and keeps your subscribers’ attention. Just like tending to a garden, it’s essential to send emails that resonate with your subscribers and bloom into fruitful connections.

But what kind of content should you plant in your email garden? That depends on your audience and their interests and likes, but here are a few ideas to help kick off your content brainstorm

  • Share your latest blog articles in your emails to help educate your audiences on trending topics, industry trends, your newest products and services, and more. 
  • Highlight your company’s diverse content, including videos, podcasts, exclusive interviews, whitepapers, reports, guides, and more.  
  • Raise awareness of your upcoming webinars and events so your recipients can register and attend. 
  • Feature user generated content to showcase how real-life customers feel about and use your products and services. 
  • Share customer reviews and testimonials to help prospective customers understand how your business has helped users who are similar to themselves. 
  • Cover trending topics to provide your own take on relevant trends your consumers care about.  
  • Share your brand story to help you understand how your brand got its start, as well as what your values and mission are. This can help audiences build a more emotional connection with your company and be more willing to buy from you.  
  • Announce new products and services to keep your prospects and customers up-to-date on your latest offerings. 
  • Send a weekly or monthly newsletter to inform your subscribers of your company’s latest news and product updates. 
  • Reward your most loyal customers with exclusive content, VIP sales and discounts, and benefits reminders. 

If you’re looking for even more email inspiration to help you brainstorm your next campaign, check out our Free Email Marketing Template Library for email ideas for every occasion. Plus, each template is completely customizable, so all you have to do is add in your copy, images, and links and you have yourself a stellar email! 


Use an email preference center.

Odds are most of your subscribers won’t want to receive every email you send. Instead, let them self-select what types of content they’re most interested in via an email preference center. They can also select how frequently they want to hear from your brand so they don’t unsubscribe due to receiving too many messages.

Every garden is plagued by weeds. In order to protect your recipients, respect global regulations, and boost your deliverability in the process, your business must be aware of and follow all applicable laws. Here are a few of the most common global regulations impacting email senders, but as always, be sure to do your research to see if any additional global or state laws apply to your business. 

Controlling the Assault of Non-Solicited Pornography and Marketing (CAN-SPAM) Act

Passed in 2003, CAN-SPAM set rules for commercial electronic messages and gave recipients the right to request that messages stop getting sent to them. There are seven main requirements senders must follow to remain CAN-SPAM compliant:

  1. Do not use false or misleading header information.
  2. Do not use deceptive subject lines.
  3. Identify the message as an advertisement.
  4. Inform recipients of where you are located.
  5. Inform recipients of how to opt-out of receiving future messages.
  6. Honor opt-out requests as promptly as possible.
  7. Monitor messages that are sent on your behalf.

Learn more about CAN-SPAM compliance in our blog post, CAN-SPAM Compliance: Breaking it Down

Canadian Anti-Spam Law (CASL) 

Do you send email to Canadian recipients? If so, the CASL applies to you. This law makes it illegal to send emails, text messages, or other electronic messages to recipients without their permission, so be sure to collect express (explicitly given) or implied (under certain conditions) consent from all of your subscribers and customers. Learn more about CASL here.

California Consumer Privacy Act

The CCPA gives Californians more control over their personal data by giving them the right to:

  • Know “what personal information is collected, used, shared or sold” by the organizations with whom they interact.
  • Delete “personal information held by businesses,” including any of the business’s own service providers.
  • Opt-out of the sale of their information.
  • Non-discrimination when exercising any CCPA privacy rights, including access to “price or service.”

This act provides state-wide privacy protections for consumers, but will only apply to businesses with gross annual revenue exceeding $25 million, businesses that generate 50% or more of their annual revenue from the sale of personal consumer information, or businesses that buy, receive, or sell the personal information of 50,000 or more consumers, households, or devices.

The General Data Protection Regulation (GDPR)

GDPR is a set of rules designed to give individuals within the European Union (EU) better control, access, and security over their personal data. The five rules apply to any business that has EU-based prospects or customers. Summarized, these rules are: 

  1. Data must be collected for a specific, lawful purpose.
  2. Data must be accurate and kept up to date.
  3. Data must be deleted or anonymized as soon as possible after the purpose for processing has been served.
  4. Data should be processed securely.
  5. A data breach should be communicated within 72 hours.

For even more detail on how GDPR affects email senders, check out our guide on the topic. 

Chapter 8: Experiment

To learn what your audiences like and what factors boost your email performance, you’ll want to experiment. Fortunately, just like tending to a garden, email marketing offers numerous variables for you to experiment with and gauge their impact.

For instance, consider these email factors ripe for A/B testing:

Audience segments: We’ll explore the benefits of segmenting your audience lists in more depth later on, but play around with sending targeted content to different segments or email lists. For example, a retailer might send two versions of a “check out our new arrivals” email to its male and female users. This can help you determine whether tailored content improves engagement.

Call-to-action (CTA): Test different CTAs, their placement, wording, and design. You can also experiment with the button’s color, size, and display text.

Content tone: Use different tones, like formal vs. casual language, to see which resonates better with your recipients. 

Personalization: Personalize your email content by including a recipient’s name or catering the email body to their interests, location, past purchases, etc. We’ll discuss the many different ways your business can personalize messages in more detail later in this guide.

Preheader text: Play around with preheader text, or the snippet of text that appears right after the subject line in a recipient’s inbox, to see if different copy positively impacts open rates.

Frequency: Experiment with how often you send your audience messages. This can help you find a balance between keeping your audience engaged while not overwhelming them.

Length of content: What is the attention span of your audience? Test whether shorter or longer emails are more effective with your subscribers. This could include testing the length of your copy or the overall email itself.

Sender email address: Try using different sender email addresses to determine if certain addresses have higher credibility or better open rates. 

Sender name: Test different sender names to determine if using a personal name, company name, or a combination yields better results. For example, you might see a higher open rate using “Sam at Segment” than “Segment Marketing.” 

Send time: Are your subscribers more likely to open your emails on specific days of the week and times of day? Test different send dates and times to identify when your audience is most likely to engage with your emails.

Single vs. multiple CTAs: While it’s general best practice to only include one CTA per email so you have your audience’s full attention, that doesn’t mean you can’t experiment to see if this is true for your subscribers. Consider testing whether a single prominent link or multiple links/CTAs leads to better click-through rates.

Social proof: No one can vouch for your products and services like your existing customers. See if including social proof elements such as customer reviews, testimonials, or user generated content in your emails boosts click-through-rates and overall engagement.

Subject line emoji: They say “a picture is worth a thousand words.” Could the same be true for emojis? Run an experiment to see if including emojis in subject lines grabs recipients’ attention and improves open rates more than plain text.

Subject line: Last but not least, we have the most classic email A/B test. Try putting two subject lines head-to-head to see which one leads to higher open rates. You can test variations in length, tone, personalization, and the use of emojis.

Chapter 9: Segment and personalize your emails



When gardening, segmentation is important. Certain plants are sun worshippers, while others prefer to stay cool in the shade. Fail to understand your plants’ wants and needs and they won’t thrive in your garden. 

The same rule applies to your email recipients. While some will want to receive every email you send, others might only be interested in a specific type of content you send (ie. your newsletters, company updates, new product announcements, etc.). Segmenting your audiences based on these preferences, you can ensure recipients only receive content they want to receive, while allowing your business to better personalize the messages you send

There are quite few ways you can segment your email lists to achieve better personalization, including by an individuals’: 

  • Gender
  • Age
  • Income level 
  • Location
  • Industry
  • Hobbies
  • Education level
  • Past purchases
  • Loyalty status
  • Interests
  • And more

But in order for audience segmentation to truly work, you need access to real-time customer data and tools that not only collect and consolidate this data on your behalf, but enable you to take action on it. 

That’s where Twilio Engage can help. Combining the power of a customer data platform and Twilio’s native customer engagement channels, like email and SMS, Twilio Engage enables businesses to build and personalize user interactions at scale. It also gives businesses access to: 

  1. A modern customer data foundation: Power all your customer experiences with trusted, real-time, first-party customer data from Twilio Segment’s leading CDP.
  2. Scalable native communications channels: Reach global customers using native channels built on the APIs trusted to send billions of communications every day.
  3. Powerful, unified orchestration and analytics: Build, activate, and measure ROI from one platform to save time and budget while improving campaign performance and efficiency.

From building custom audiences to orchestrating real-time customer journeys, your company can personalize every experience and communication around real-time user behaviors, traits, and intent signals. More targeted emails means better engagement for your business and more relevant emails for your customers — a win-win for everyone.

Chapter 10: Analyze performance

Now it’s time to step back and evaluate how effectively your messages are taking root with your audience and achieving your objectives. Here’s a brief step-by-step guide on how email senders can analyze the performance of their emails:

  1. Define goals and key metrics: First determine the goals of your email campaign. Are you aiming for higher open rates, click-through rates, conversions, or something else? Identifying the key metrics that align with these goals will help you evaluate success moving forwards. 
  2. Leverage your email service provider’s tools: From opens to clicks to bounces, the average email message generates around nine unique events. To help senders keep track and improve these metrics and more, most email service providers make evaluating campaign performance easy with helpful dashboards and reporting features.

    For example, Twilio SendGrid’s Deliverability Insights showcases insightful metrics to optimize your email deliverability, like delivery rate, bounce rate, unique opens, and more. Plus, custom metrics like our SendGrid Engagement Quality Score (SEQ) gives you insight into how wanted your emails are so you can improve your chances of getting to the inbox.

    For more insight into your email performance, Twilio SendGrid’s Email Statistics reporting helps you track the potential of your one-time sends and ongoing automations for both marketing and transactional email campaigns. You can easily keep an eye on open rates, click rates, unsubscribes, and more in real-time, so you can understand which messages are falling short of your expectations and which are landing well with your audiences. 
  3. Find out what’s working and what isn’t: With all your data in one place, you can quickly identify what’s working, identify areas of growth, and make informed decisions about the future of your email program. Every email metric gives you valuable insights into what your customers like and don’t like, so listen to what they’re telling you and take action to create more content they enjoy. 

Consider collecting recipient feedback via surveys

Sometimes email metrics don’t tell the full story. If you want qualitative feedback from your recipients, try leveraging surveys to collect more information on their preferences and opinions of your emails. These insights can help guide your content creation and sending practices.


Keep track of your sender reputation with Twilio SendGrid’s Sender Quality Score

SendGrid Quality Score (SEQ) helps senders understand the quality of their email program and how “wanted” their email is. The score is calculated based on cues from mailbox providers and performance metrics like opens, bounces, blocks, spam complaints and engagement recency. This means the higher your SEQ score, the more likely you are to land in your recipients' inboxes.

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When growing an email program, automation acts like a well-timed watering system for your garden. It ensures that your emails reach the right recipient at precisely the right moment, all without you needing to grab a watering can! Plus, it can be used for both marketing and transactional purposes. Sending extremely user-specific messages in a responsive way can cultivate customer loyalty and retention, drive revenue, and sprout increased conversions. 

Here are a few examples of emails you can automate:  

Nurture emails

Nurture emails can help guide prospects to the next step in the sales funnel by sharing product information, company details, client testimonials, and more. By building and automating nurture emails based on specific customer personas, your business can better cater your message to their unique pain points, interests, objectives, and behaviors, which can improve the likelihood your recipients ultimately take your desired action. 

Using automation, you can enroll new users in your nurture campaigns based on the criteria of your choosing (gender, income level, geographical location, company size, job title, etc.) or even based on behavioral data (like web pages viewed or past purchases). For example, if someone signs up for your free product trial, you can enroll them in a multi-email nurture cadence that looks something like this:

  1. Email 1: How to get the most of your free trial
  2. Email 2: Key features users in [recipient’s industry] find helpful
  3. Email 3: The benefits of upgrading to a paid plan
  4. Email 4: Testimonials from customers in [recipient’s industry] 

With these emails, users will be more familiar with the benefits of your tool and business and more willing to convert at the end of their free trial. 

Check out Lead Nurturing 101: How to Nurture Leads for more examples and best practices. 

Welcome emails

Welcome emails typically consist of 3-5 messages that onboard new customers to your email list and provide a warm introduction to your brand. They can share more about your products and services, your company’s mission and values, what your customers love most about your business, and more — really anything that puts your business’ best foot forward.

Once a new subscriber signs up to receive your emails, you can enroll them in your welcome email cadence and start earning their trust. Check out our 11 Best Welcome Email Examples (How to Write Welcome Emails) blog for even more tips on how to wow your subscribers from day-one. 

Behavior based emails

You can also use automation to trigger emails based on user behavior. One popular example of this is abandoned cart emails. When a user puts an item in their cart but fails to purchase it within a given time period, your business can automatically send them a reminder email to encourage them to complete their purchase. You can even personalize these messages to include the exact item or items the user was considering to entice them to return. 

Sending manual abandoned cart emails at scale is almost impossible, but with automation, you can relax knowing these emails are firing without you having to lift a finger. That means better experiences for your customers and the chance to win back lost revenue for your business. 

Of course, abandoned cart emails aren’t the only behavior-based automations you can build. Consider building unique nurtures for when a recipient enrolls in a free trial, downloads a piece of content, achieves an account milestone, and more. 

Birthday and anniversary emails

Wishing a user a happy birthday or congratulating them on their anniversary of doing business with your company are fun emails that can help increase customer loyalty. Just set up a brief workflow to send these emails on their birth date or account signup date and you’re good to go! You can even add a discount code or free gift to thank them for their business and wish them well on their special day. 

See some eye-catching birthday email examples in our post, Celebrate Customers With an Automated Happy Birthday Email Campaign.

Re-engagement emails 

Part of scaling any email program is regular list maintenance, or ensuring your subscriber list is made up of users who want to hear from your brand. Over time, certain subscribers might stop engaging with your messages. Instead of removing them from your list, consider giving them one last chance to continue receiving your messages with a win-back, or re-engagement campaign

Just designate your specific enrollment criteria (for example, haven’t opened or clicked an email in over three months) and build an email telling your recipients that you’ve noticed their inactivity and will be removing them from your list unless they request to continue receiving your messages. Your business can then remove any individuals who don’t reply from your email list, ensuring you only keep users who want to receive your messages.

Chapter 12: Conclusion

Like cultivating a garden, growing your email program requires patience, care, and dedication. Just as a gardener watches their plants grow from seedlings into magnificent blooms, you have the power to transform your email program into a vibrant, thriving ecosystem. 

When it comes to building a solid foundation for your email program and maintaining a healthy and engaged subscriber list, Twilio SendGrid is here to help. Our Email API has everything you need to create an exceptional email program and deliver your messages at scale:

  • Reliable and fast email delivery ensures every one of your emails lands in customer inboxes
  • One central email platform empowers all of your developers, marketers, and business leaders to collaborate seamlessly
  • Top security measures to keep your account safe and protect your brand reputation
  • The tools you need to orchestrate tailored engagement and maximize connections with behavior-triggered emails
  • Interactive dashboards that help you understand overall email program health and pinpoint where they can improve deliverability. 
  • And more

Scaling an email program is a dynamic process that looks different for every business. Like a garden, your email strategy will be constantly evolving and changing as you tend to it. By choosing the right tools to help, you can embrace this natural progression and watch as your email program flourishes from seedling to full bloom.

Ready to cultivate your email program with Twilio SendGrid? Learn more on our pricing page or get started for free by creating an account now

Get Started with SendGrid

SendGrid helps you focus on your business without the cost and complexity of owning and maintaining an email infrastructure. And with a full-featured marketing email service that offers a flexible workflow, powerful list segmentation, and actionable analytics, all of your email needs are met in one simple platform.