What Is Email Marketing? The Channel You Own, Explained Properly

“Does anyone even read emails anymore?” The founder of a spice brand asked me this while we were planning her festive season, and she meant it. Her team was pouring energy into Instagram Reels, and email felt like something her parents’ bank sent. My answer was that her customers read the emails they asked for, from brands they like, about things they care about. And more importantly, email was the only channel on her plan where she owned the audience.

That last point is what makes email different. An Instagram follower can stop seeing your posts because of an algorithm change you’ll never be told about. An ad audience disappears the moment you stop paying. An email list is a direct line to people who said “yes, contact me”, and it moves with you if you change platforms. In this guide I’ll cover how email marketing works, which emails do the real work, why the most quoted metric is misleading and how to set it up so it keeps paying back.

What email marketing actually means

In plain terms, email marketing is sending useful, relevant emails to people who’ve agreed to hear from you, so they keep coming back.

The formal definition is that email marketing is the use of email to communicate with prospects and customers who have opted in to receive messages, with the aim of building relationships, driving sales and encouraging loyalty. It covers three broad kinds of email:

• Campaigns. One-off sends to your list or a segment, like a newsletter, a product launch or a sale announcement.
• Automated flows. Sequences triggered by what someone does, such as signing up, browsing a product, abandoning a cart or buying for the first time.
• Transactional emails. Order confirmations, shipping updates and password resets. They aren’t marketing in the strict sense, but they’re some of the most-read emails you’ll ever send, and they shape how people feel about your brand.

The key word in the definition is permission. Email marketing only works on people who chose to receive it. Sending to anyone else is spam, and it damages your ability to reach the people who did say yes.

How email marketing works

Email marketing runs on a few connected pieces.

The list. People join through sign-up forms, checkout opt-ins, lead magnets like guides or quizzes, and in-store or event sign-ups. The best lists are built by offering something worth an email address, not by hiding a checkbox.

The email service provider. Tools like Mailchimp, Klaviyo, Brevo and many others store your list, send your emails, run automations and report results. Pick one that connects properly to your store or CRM so it knows what customers have bought.

Segmentation. Instead of sending everything to everyone, you group people by what they’ve done: first-time buyers, repeat customers, people who browsed a category, subscribers who haven’t opened in months. Relevant emails get read, and irrelevant ones get ignored or reported.

Deliverability. Your email is only useful if it lands in the inbox. That depends on authenticating your sending domain with SPF, DKIM and DMARC records, keeping spam complaints low, removing addresses that bounce or never engage, and making unsubscribing easy. The big mailbox providers have been tightening their rules for bulk senders, so this is no longer optional.

Measurement. Clicks, conversions, revenue per email, unsubscribes and spam complaints tell you what’s working. Open rates are less reliable than they used to be, for reasons covered below.

The automated emails that do the heavy lifting

Most people picture email marketing as newsletters and sale blasts. In practice, a handful of automated flows often do much of the commercial work, because they arrive at exactly the moment a customer is paying attention.

• Welcome series. Sent right after someone subscribes. It introduces the brand, delivers whatever you promised at sign-up and gives a reason to make a first purchase.
• Abandoned cart and browse flows. A reminder when someone leaves items in a cart or looks at a product without buying. Timely, helpful and usually well received.
• Post-purchase flow. Thanks, how to use the product, what to expect and, later, a request for a review.
• Replenishment reminders. For consumables like coffee, pet food or skincare, a nudge timed to when the customer is likely to run out.
• Win-back flow. A message to customers who haven’t bought in a while, with a reason to return.

Set these up once and they run every day in the background. If you map your customer journey, each of these flows sits at a moment where a well-timed email helps the customer take the next step.

A worked example: a welcome series for a pet food brand

This is a hypothetical example with example numbers. A pet food brand in Pune gains about 1,200 new email subscribers a month through a website pop-up offering a free puppy feeding guide. Until now, new subscribers just get added to the weekly newsletter.

Tracking shows about 3% of new subscribers make a first purchase within 30 days. That’s roughly 36 first orders a month, and at an average order value of ₹1,400, about ₹50,400 in first-order revenue.

The brand builds a three-email welcome series. Email one arrives immediately with the feeding guide and a short story about why the founders started the brand. Email two, two days later, explains how to switch a dog’s food safely and shares reviews from owners of similar breeds. Email three, five days after sign-up, offers ₹150 off a first order, valid for a week.

After two months, around 8% of new subscribers buy within 30 days: about 96 first orders, or ₹1,34,400 in revenue. The discount costs 96 × ₹150 = ₹14,400, leaving far more than before. More importantly, those 96 new customers now enter the post-purchase and replenishment flows, which is where a pet food brand makes most of its money.

Email marketing vs social media marketing

Email and social media are often treated as competitors for the same budget. They do different jobs.

	Email marketing	Social media marketing
Who owns the audience	You do: the list is yours	The platform does
Who decides who sees a message	You, by list and segment	The platform’s algorithm
Best at	Nurturing, selling and retaining known contacts	Discovery and reaching new people
Personalisation	High: by behaviour, purchase and preferences	Limited on organic posts
Main risk	Poor deliverability or list fatigue	Algorithm changes and falling organic reach

Social media is where many people discover you. Email is where you turn that discovery into a relationship you control. The practical move is to use social content, ads and your website to invite people onto your list, then let email do the nurturing and selling.

How to set up email marketing

1. Choose an email service provider that fits. Make sure it connects with your store, website or CRM, so it can trigger emails based on real behaviour.
2. Authenticate your sending domain. Set up SPF, DKIM and DMARC before you send anything at volume. Your provider’s help pages will walk you through it.
3. Build the list with permission and a reason to join. Offer something useful at sign-up, like a guide, a quiz result or early access, and make it clear what people will receive.
4. Launch the welcome series first. It reaches every new subscriber at the moment of highest interest. Then add abandoned cart and post-purchase flows.
5. Plan a regular campaign rhythm. Decide what you’ll send and how often, and mix helpful content with offers so emails are welcome, not just promotional.
6. Write each email for one reader and one action. A clear subject line, a single main point and one obvious button beat a crowded newsletter.
7. Segment as the list grows. Treat new subscribers, first-time buyers, loyal customers and lapsed ones differently.
8. Clean the list regularly. Remove hard bounces and, after a re-engagement attempt, people who haven’t engaged in a long time.

Common email marketing mistakes

Buying or scraping email lists. It looks like a shortcut to a big audience. In reality, those people never asked to hear from you, they report you as spam, and your emails stop reaching even the customers who wanted them.

Judging everything by open rate. Privacy features in some email apps record opens automatically, so open rates are inflated and inconsistent. Judge emails by clicks, conversions and revenue instead.

Sending only discounts. If every email is a sale, customers learn to wait for the next one and ignore the rest. Give people reasons to open that aren’t price.

Treating everyone the same. A first-time subscriber and a customer who has bought ten times need different emails. One message to the whole list serves neither well.

Making unsubscribing hard. Hidden or broken unsubscribe links push people to hit the spam button instead, which hurts your deliverability far more than a clean unsubscribe.

How to tell if your email marketing is healthy

Industry averages vary widely by sector, list quality and how opens are counted, so I won’t quote one. These signals tell you more:

• Emails land in the inbox, and spam complaints stay very low.
• Click rates and revenue per email are steady or improving over time.
• Automated flows bring in a meaningful share of email revenue every week without extra effort.
• Unsubscribes rise only slightly after big sends, not sharply.
• The list grows mainly through sign-ups you earned, and new subscribers go on to buy.
• Repeat customers engage with your emails and mention them unprompted.

Key takeaways

• Email marketing reaches people who gave you permission, on a list you own.
• Campaigns get the attention, but automated flows like welcome, cart and post-purchase emails often do much of the selling.
• Deliverability depends on domain authentication, low complaints and a clean list.
• Open rates are unreliable now. Judge emails by clicks, conversions and revenue.
• Use social media to find people and email to build the relationship.