Email Marketing Best Practices for Building & Maintaining Relationships

Email marketing is one of an organization’s most powerful digital marketing tools. Why? Because people on your lists have already “opted in” to your brand. You’re not starting from scratch; they’ve already given you (some of) their attention. The exciting challenge is to strategize ways to entice and engage that audience on a regular basis.

In this post, we’ll cover the essentials of effective email marketing: from crafting compelling subject lines to designing mobile-friendly messages that drive clicks. You’ll learn which metrics matter most for tracking success, how to boost your open and click-through rates, and what small changes can make a big impact on engagement.

Whether you’re building a full email campaign strategy from scratch or just looking to refine your ongoing efforts, these best practices will help you connect with your audience in more innovative, more meaningful ways.

Ready to turn insights into results? Big Sea can help you build email strategies that inspire action and grow your mission.

Key Elements of an Effective Email Marketing Strategy

An effective email marketing strategy starts with understanding your audience and building every message around their needs. The most successful email marketing campaigns use data and empathy in equal measure—pairing segmentation and smart workflows with storytelling to build trust and connect on a human level. Your goal isn’t just to send more emails; it’s to send meaningful messages that meet your supporters where they are in their “customer journey,” whether they’re first-time donors, long-time advocates, or volunteers ready to take the next step.

Every email you send should deliver relevant content that strengthens your relationship with your community. That might mean an update about impact in the field, a timely call to action (CTA), or a simple thank-you that makes someone feel seen. Strong campaigns are built on email content that’s mobile-friendly and accessible, subject lines that earn attention, and a clear strategy that ensures every message supports a larger goal.

Behind the scenes, automation helps maintain consistent, personal communication. Pre-built workflows allow you to nurture different segments of your audience over time, guiding each group through a thoughtfully mapped-out process. By tracking your progress with well-defined metrics, you can continually refine your approach and ensure that every email contributes to your mission’s bigger picture.

Best Practices for Establishing Relationships: Email List Building

First, let’s talk about building your email list. List building can be achieved in a variety of ways, including social media contests, advertising, website offers, etc. But the most foundational strategy for establishing an email relationship with a customer is through a website sign-up form (aka an email opt-in form). As your SEO, digital advertising, social media, and PR efforts drive more traffic to your website, it’s incredibly valuable to capture as many visitors’ emails as you can.

Email Sign-Up Forms

Sign-up forms should be placed in numerous locations on your website, with the most common being:

• Homepage (embedded form and/or pop-up)
• Blog (embedded form and/or pop-up)
• Article/product page sidebar
• Landing pages (embedded form and/or pop-up)
• Website footer

Your homepage, landing pages, and high-traffic blog or service pages are the most important locations to place a sign-up form. If you’re using an embedded form, be sure to position this as close to the top of your page as possible so visitors don’t miss it (i.e., “above the fold”).

Embedded forms and pop-ups should be clear, accessible, and easy to use. In general, people prefer sign-up forms that don’t demand too much time or energy. I like to stick to two or three fields. Here are a few options:

• Email address
• First name
• Last name

or

• Email address
• First name
• Zip code

or

• Email address
• Zip code

In some cases, it may be most suitable for design or user experience to ask for an email only. To make a final decision about the information you’re asking for, I strongly recommend walking yourself, your employees, and your friends through the sign-up process to see how it feels. Also, make sure that the information you ask for is the most critical to your marketing efforts. For example, if your services are location-specific, you’ll likely want to prioritize zip code over a name.

Best Practices for Maintaining Customer Relationships: Email Design, List Organization & Subject Lines

So now that you’ve earned someone’s email address, what you do next will either cement or break the relationship.

Create Branded Email Templates

Email design and templates should be a reminder of your brand! When your new subscriber receives their first email or welcome message, you want them to remember who you are. Therefore, be sure to include imagery, colors, and other design elements similar to those on your website.

Organize Your Emails for Conversion

The process of developing emails is similar to designing a website: you must present your information in a way that enhances the user experience and drives clicks. Here are some simple best practices for achieving that:

• Organize content by priority and for readability.
• Make calls to action clear and easy to click.
• Use buttons when possible (they have a higher click rate than text links).
• Link calls to action directly to the desired conversion area (e.g., donations, event landing pages, purchase forms, etc.).
• Limit the number of calls to action: a singular goal is ideal, especially for sales-focused emails.

Organize Your Email List & Use Segmentation

List organization is a big deal! Messy lists result in poorly executed campaigns and increase the likelihood of errors. Organized lists usually lead to better engagement and fewer unsubscribes.

If possible, create a single master marketing list that contains all your subscribers. Why one list? With most email platforms, you pay per subscriber. Multiple lists often cause duplicate emails and, therefore, duplicate costs.

Organize that list into groups and segments. Some campaigns don’t apply to everyone on your list. Creating groups or segments of your list allows you to target the most relevant client base. Plus, segmentation reduces unsubscribes and spam complaints and increases engagement.

Start with basic demographics—location, age, or role —then layer in behavioral data, such as past donations, event attendance, or content engagement. For e-commerce or donation-based organizations, segmenting by purchase or giving history helps tailor appeals. The more specific your segments, the more relevant and compelling your emails will be.

Best Practices for Writing Effective Email Subject Lines

Your subject line is the first impression your email makes—and often the deciding factor in whether your message is opened or ignored. Great subject lines balance clarity with curiosity and stay true to your organization’s mission and voice. Keep them short, meaningful, and relevant to your audience’s interests.

Here are a few best practices to guide your next campaign:

• Keep it concise. Aim for fewer than 50 characters so your full subject line shows on mobile devices.
• Lead with value. Tell readers what they’ll gain by opening—insight, inspiration, or a tangible way to make an impact.
• Align with your email content. Make sure your subject line accurately reflects the message inside—integrity drives long-term engagement.
• Personalize when possible. Don’t overdo it every time, but using a recipient’s name, location, or past engagement can make the message feel personal and relevant.
• Avoid vague promises. Supporters value transparency and trust.
• Create gentle urgency. Phrases like “Last chance to double your impact” or “See your gift in action today” can motivate action without putting pressure on recipients.
• Test and learn. A/B test tone, structure, and emotional appeal across segments to uncover what resonates with your community.

Strong subject lines do more than improve your open rates; they reinforce trust, deepen relationships, and invite your audience into the ongoing story of your mission.

That said, however, there isn’t a secret sauce that works for everyone. Which subjects work best for your organization will hinge in large part on audience and relevance. That’s why A/B testing (which we discuss below) is one of the best ways to learn as you go.

A/B Testing Subject Lines

A/B testing (aka variable-testing emails) can be set up in a variety of ways, with the most common being an A/B test of two or more different subject lines based on open-rate results. In a nutshell, A/B testing takes the guesswork out of writing subject lines. It helps you determine which subject lines resonate most with your subscribers and then automatically delivers the most popular subject line to the majority of your list. Like list segmentation, A/B testing is a tool I use for the majority of my campaigns, and it always pays off!

Best Practices for Improving Email Open Rates and Click-Through Rates

The key to improving open and click-through rates is to optimize every step of the email experience—from the moment your message lands in the inbox to the moment a reader takes the next step toward your mission.

Start by sending the right types of email for your audience and goals. Welcome emails, campaign updates, and thank-you messages each serve a different purpose within the donor journey. Matching content to intent ensures your messages feel relevant rather than spammy, helping reduce bounce rates and increase engagement over time.

To lift open rates, focus on trust and timing. Use a recognizable sender name, avoid misleading subject lines, and keep your cadence consistent so readers know what to expect. Segment your audience so each person receives relevant content tailored to their relationship with your organization. When messages feel personal and purposeful, they’re far more likely to be opened.

Once they’ve opened your email, guide readers to a single clear call to action. Whether you’re inviting them to donate, read a story, or sign up for an event, simplicity is powerful: too many links can overwhelm or distract. Strong design and short, emotionally resonant copy make it easy for readers to take the next step, improving conversion rates and deepening engagement.

Best Practices for Testing and Monitoring Your Email Campaigns

To make the most of your efforts, you need to know what’s working and what isn’t. The right email marketing tools enable you to track performance for every email message and identify opportunities to improve engagement. Whether you’re using HubSpot, Mailchimp, or another email service provider (we’re particular fans of HubSpot), your data tells the story of how your supporters interact with your communications and where you can better connect with your target audience.

Start by keeping a close eye on key metrics: open rates, click-through rates, and conversion rates show how well your message resonates, while unsubscribe rates and bounce rates highlight areas for refinement. Tracking these numbers over time reveals trends that help you adjust your approach—whether that means optimizing send times, refreshing design, or delivering more engaging content.

Testing is just as necessary as tracking. Use your email marketing platform to run A/B tests on subject lines, calls to action, visuals, and timing. Even small changes can have a measurable impact on results. Testing also helps you understand how different marketing channels—like social media, paid ads, or SMS notifications—interact with your email strategy, giving you a more holistic view of your campaign performance.

Finally, don’t forget about long-term relationship-building. Revisit your data regularly to identify lapsed subscribers and create re-engagement campaigns tailored to their interests. Many email service providers make this easy with automated workflows that reintroduce supporters to your mission through personalized storytelling and targeted outreach.

By combining meaningful metrics, strategic testing, and ongoing optimization, you’ll transform your email program from a set of standalone messages into a dynamic communication channel that informs, inspires, and drives action.

Best Practices for Designing Mobile-Friendly Emails

Mobile devices have become the primary touchpoint for most subscribers, which means mobile optimization needs to be part of your marketing strategy. A well-designed mobile email enhances the customer experience, improves deliverability, and keeps your audience engaged at every stage of their lifecycle with your organization.

Start with a responsive design that automatically adjusts to different screen sizes. Single-column layouts, generous spacing, and clear hierarchy ensure your message is easy to read and navigate on any device. Keep paragraphs short, use large tappable buttons for calls to action, and select clean, legible fonts that display consistently across email clients. Always test your layout on both Android and iOS devices before sending.

Your preview text—that short snippet that appears next to your subject line in the inbox—is another critical piece of real estate. Use it to reinforce your subject line or highlight the main takeaway of the message. This small detail can make the difference between an opened message and a missed opportunity.

Consider adding interactive elements, such as GIFs, image carousels, or quick polls, to capture readers’ attention without overwhelming them. Just be sure these features enhance your story, not distract from it. Accessibility matters too—use sufficient color contrast, descriptive alt text, and clear CTAs for readers using screen readers or smaller displays.

Craft Moving Messages with Big Sea

Your mission deserves a campaign that inspires action. At Big Sea, we help purpose-driven organizations use email marketing to do just that. From strategy and design to automation and analytics, we’ll help you build more intelligent workflows, craft messages that resonate, and turn every send into a meaningful touchpoint.

Whether you’re nurturing donors, engaging volunteers, or driving awareness, our team knows how to align your communications with the heart of your mission. Let’s build something that moves people and moves your organization forward.