Revision 1
Email Marketing

@namkyu · Sep 1, 2026, 8:19 AM
Added email marketing workflow, tools, automation, deliverability, and compliance.
+23,432−0
+Email marketing is the use of email to communicate with subscribers, customers, and prospects for purposes such as sales, product education, retention, announcements, and relationship building.
+ 
+Businesses can use email marketing to promote products, recover abandoned carts, onboard new users, send newsletters, announce launches, educate customers, and automatically follow up based on user behavior.
+ 
+Unlike social media, an email list is typically built around direct subscriber relationships rather than dependence on a public-feed algorithm.
+ 
+# Quick Facts
+ 
+ 
+| Item                                 | Details                                                                 |
+| ------------------------------------ | ----------------------------------------------------------------------- |
+| Main goal                            | Generate sales, retention, engagement, and repeat visits                |
+| Common uses                          | Newsletters, promotions, onboarding, abandoned carts, product education |
+| Coding required                      | No for most campaigns                                                   |
+| Common tools                         | Mailchimp, Klaviyo, HubSpot                                             |
+| Free tools available                 | Yes                                                                     |
+| Mailchimp starting paid plan example | From about $20/month                                                    |
+| Klaviyo free plan                    | Up to 250 profiles and 500 emails/month                                 |
+| Gmail bulk-sender threshold          | About 5,000 messages/day to personal Gmail accounts                     |
+| Key technical requirements           | SPF, DKIM, DMARC, unsubscribe support                                   |
+| Difficulty                           | Beginner to advanced                                                    |
+ 
+ 
+# How Email Marketing Works
+ 
+Email marketing usually follows a simple process:
+ 
+Visitor joins list → Subscriber receives emails → Emails educate or promote → Subscriber clicks → Subscriber purchases or takes another action
+ 
+The important part is not simply sending more email.
+ 
+A useful email program depends on:
+ 
+- Permission
+- Relevant content
+- Segmentation
+- Timing
+- Deliverability
+- Clear calls to action
+- Measurement
+ 
+# Main Types of Email Marketing
+ 
+## Newsletter
+ 
+A newsletter is sent regularly to subscribers.
+ 
+Common content includes:
+ 
+- Industry news
+- New articles
+- Product updates
+- Company updates
+- Curated resources
+- Educational content
+ 
+Newsletters are useful for staying in contact with an audience even when there is no immediate promotion.
+ 
+## Promotional Email
+ 
+Promotional emails are designed to generate a sale or another direct action.
+ 
+Examples include:
+ 
+- Product launch
+- Limited-time discount
+- Seasonal sale
+- New collection
+- Event promotion
+- Upgrade offer
+ 
+Promotional emails should clearly explain:
+ 
+- Offer
+- Benefit
+- Deadline if applicable
+- Call to action
+ 
+## Welcome Email
+ 
+A welcome email is sent after someone subscribes or creates an account.
+ 
+It may include:
+ 
+- Introduction
+- What to expect
+- Useful resources
+- Product explanation
+- Discount
+- Next step
+ 
+Welcome emails are often part of an automated sequence rather than a single message.
+ 
+## Onboarding Sequence
+ 
+Onboarding emails help new users understand a product or service.
+ 
+A sequence might include:
+ 
+- Account setup
+- Core feature introduction
+- Tutorial
+- Use case
+- Success example
+- Upgrade invitation
+ 
+This is particularly common for SaaS businesses.
+ 
+## Abandoned Cart Email
+ 
+E-commerce businesses can send reminders when a customer adds a product to a cart but does not complete the purchase.
+ 
+A sequence may include:
+ 
+- Reminder
+- Product image
+- Benefits
+- Reviews
+- Discount if appropriate
+ 
+The exact strategy should reflect the store's economics rather than automatically offering a discount.
+ 
+## Post-Purchase Email
+ 
+Post-purchase emails can include:
+ 
+- Order confirmation
+- Usage instructions
+- Product education
+- Review request
+- Cross-sell
+- Reorder reminder
+ 
+These messages can improve customer experience and repeat purchases.
+ 
+## Re-Engagement Email
+ 
+Re-engagement campaigns target subscribers who have stopped opening or clicking emails.
+ 
+Possible messages include:
+ 
+- Preference update
+- New offer
+- Content reminder
+- Subscription confirmation
+ 
+Inactive subscribers may eventually be removed from active marketing lists to protect deliverability and reduce software costs.
+ 
+# Building an Email List
+ 
+Email marketing begins with permission-based list growth.
+ 
+Common methods include:
+ 
+- Website signup form
+- Newsletter signup
+- Lead magnet
+- Free tool
+- Discount
+- Account creation
+- Webinar registration
+- Checkout opt-in
+- Event registration
+ 
+Avoid purchasing random email lists.
+ 
+Purchased lists can create:
+ 
+- Spam complaints
+- Poor engagement
+- Deliverability problems
+- Legal risk
+- Platform-account problems
+ 
+A smaller engaged list can be more valuable than a large list of people who never asked to receive messages.
+ 
+# Lead Magnets
+ 
+A lead magnet gives visitors a reason to subscribe.
+ 
+Examples include:
+ 
+- Checklist
+- Template
+- Guide
+- Calculator
+- Free course
+- Report
+- Industry data
+- Coupon
+- Free trial
+ 
+The lead magnet should attract the type of subscriber the business actually wants.
+ 
+A broad giveaway may generate many subscribers who never become customers.
+ 
+# Segmentation
+ 
+Segmentation divides subscribers into groups.
+ 
+Possible segments include:
+ 
+- New subscribers
+- Customers
+- Non-customers
+- High-value customers
+- Recent purchasers
+- Inactive users
+- Product interest
+- Geographic location
+- Engagement level
+ 
+Segmentation allows different users to receive different messages.
+ 
+For example:
+ 
+A customer who already purchased a product should not necessarily receive the same introductory campaign as a first-time visitor.
+ 
+# Personalization
+ 
+Personalization can include more than inserting a first name.
+ 
+Useful personalization may be based on:
+ 
+- Previous purchases
+- Viewed products
+- Account activity
+- Location
+- Subscription type
+- Customer lifecycle stage
+ 
+The goal is to send more relevant messages rather than simply adding personal data for appearance.
+ 
+# Email Automation
+ 
+Automation sends emails when a specific event happens.
+ 
+Common triggers include:
+ 
+- Subscription
+- Account creation
+- Purchase
+- Abandoned cart
+- Trial expiration
+- Product usage
+- Inactivity
+- Birthday
+- Renewal date
+ 
+For example:
+ 
+New signup → Welcome email → Product tutorial → Use-case email → Upgrade offer
+ 
+Automation is valuable because the sequence continues without manually sending each email.
+ 
+# Campaign vs Automation
+ 
+A campaign is usually sent at a specific time to a selected audience.
+ 
+Examples:
+ 
+- Friday newsletter
+- Black Friday promotion
+- Product launch
+ 
+An automation is triggered by user behavior or a lifecycle event.
+ 
+Examples:
+ 
+- Welcome sequence
+- Cart abandonment
+- Re-engagement
+- Post-purchase sequence
+ 
+Most mature email programs use both.
+ 
+# Writing an Email
+ 
+A marketing email generally includes:
+ 
+- Sender name
+- Subject line
+- Preview text
+- Main message
+- Call to action
+- Unsubscribe option
+ 
+The email should make the intended action clear.
+ 
+Avoid unnecessary complexity.
+ 
+A simple email with one clear message can perform better than a visually complex message containing many unrelated offers.
+ 
+# Subject Lines
+ 
+Subject lines influence whether subscribers choose to open an email.
+ 
+Useful approaches include:
+ 
+- Clear benefit
+- Specific topic
+- Curiosity
+- Urgency when genuine
+- Relevant announcement
+ 
+Avoid deceptive subject lines.
+ 
+The subject should accurately represent the message.
+ 
+# Calls to Action
+ 
+A call to action tells the subscriber what to do next.
+ 
+Examples:
+ 
+- Shop now
+- Read the guide
+- Start free trial
+- View pricing
+- Complete setup
+- Book a demo
+ 
+Do not overload every email with many competing actions unless the newsletter format requires several destinations.
+ 
+# Email Design
+ 
+Marketing emails can be:
+ 
+- Plain text
+- Lightly formatted
+- Fully designed HTML
+ 
+The right style depends on the business.
+ 
+E-commerce brands may benefit from product images and visual layouts.
+ 
+Founder newsletters or B2B messages may intentionally look simpler and more personal.
+ 
+Always check mobile readability.
+ 
+# Mobile Optimization
+ 
+Many users read email on phones.
+ 
+Check:
+ 
+- Text size
+- Button size
+- Image width
+- Spacing
+- Subject length
+- Load speed
+- Layout
+ 
+Test the email before sending it to the full list.
+ 
+# Deliverability
+ 
+Deliverability refers to whether emails successfully reach recipients rather than being rejected or filtered.
+ 
+Important factors include:
+ 
+- Sender reputation
+- Authentication
+- Spam complaints
+- Engagement
+- Sending behavior
+- List quality
+- Unsubscribe handling
+ 
+A technically successful send does not guarantee that the message reaches the inbox.
+ 
+# SPF
+ 
+SPF allows a domain to specify which servers are authorized to send email on its behalf.
+ 
+It helps receiving mail systems identify unauthorized senders.
+ 
+# DKIM
+ 
+DKIM attaches a cryptographic signature to outgoing email.
+ 
+Receiving providers can use the signature to confirm that the message was authorized by the sending domain and was not altered in transit.
+ 
+# DMARC
+ 
+DMARC builds on SPF and DKIM and provides instructions for how receiving providers should handle messages that fail authentication checks.
+ 
+It also supports reporting.
+ 
+Businesses sending significant email volume should understand all three technologies.
+ 
+# Gmail Sender Requirements
+ 
+Google currently requires all senders sending messages to Gmail accounts to follow baseline authentication and delivery requirements.
+ 
+For senders sending around **5,000 or more messages per day to personal Gmail accounts**, additional requirements apply.
+ 
+These include:
+ 
+- SPF
+- DKIM
+- DMARC
+- TLS
+- Valid DNS configuration
+- Low spam rates
+- Domain alignment
+- One-click unsubscribe for marketing and subscribed messages
+- A visible unsubscribe link
+ 
+Google currently recommends keeping spam rates reported in Postmaster Tools below **0.3%**.
+ 
+Once Google classifies a sender as a bulk sender, that classification does not currently expire.
+ 
+# Unsubscribe
+ 
+Marketing email should provide an easy way to stop receiving messages.
+ 
+Do not hide or intentionally complicate the unsubscribe process.
+ 
+Google requires qualifying bulk marketing senders to provide one-click unsubscribe.
+ 
+Legal requirements also vary by country.
+ 
+# CAN-SPAM
+ 
+In the United States, commercial email is regulated by the CAN-SPAM Act.
+ 
+Businesses sending promotional email should review current FTC requirements.
+ 
+Important areas include:
+ 
+- Accurate sender information
+- Non-deceptive subject lines
+- Clear identification where required
+- Physical postal address
+- Opt-out mechanism
+- Honoring unsubscribe requests
+ 
+Email regulations vary internationally, so businesses sending across markets should check applicable local laws.
+ 
+# Measuring Email Marketing
+ 
+Important metrics can include:
+ 
+- Delivery rate
+- Bounce rate
+- Open rate
+- Click rate
+- Unsubscribe rate
+- Spam complaint rate
+- Conversion rate
+- Revenue
+- Revenue per recipient
+ 
+Do not evaluate an email program using only open rate.
+ 
+Privacy features and email-client behavior can make opens less reliable than direct business outcomes such as clicks and purchases.
+ 
+# Click-Through Rate
+ 
+Click-through rate measures how many recipients clicked a link.
+ 
+A high click rate can indicate:
+ 
+- Relevant offer
+- Strong call to action
+- Good audience targeting
+- Useful content
+ 
+However, the final goal is often conversion rather than the click itself.
+ 
+# Conversion Rate
+ 
+A conversion occurs when the email contributes to the desired action.
+ 
+Examples:
+ 
+- Purchase
+- Demo booking
+- Trial signup
+- Registration
+- Upgrade
+ 
+A campaign with fewer clicks but more purchases may be more valuable than one with many clicks but little revenue.
+ 
+# Revenue Attribution
+ 
+E-commerce and marketing platforms can attribute purchases to email campaigns and automations.
+ 
+Attribution models vary.
+ 
+Do not assume reported revenue means the email was the only reason the customer purchased.
+ 
+Use the metric as a directional tool rather than an absolute representation of causality.
+ 
+# Email Marketing Tools
+ 
+## Mailchimp
+ 
+Mailchimp provides:
+ 
+- Email campaigns
+- Automation
+- Templates
+- Signup forms
+- Segmentation
+- Reporting
+ 
+Its current pricing page lists:
+ 
+- Free options for small contact lists
+- Standard starting around $20/month after trial
+- Premium starting around $350/month in the current displayed configuration
+ 
+Pricing depends on contact count and sending limits.
+ 
+Mailchimp can be useful for:
+ 
+- Newsletters
+- Small businesses
+- General email campaigns
+- Basic automation
+ 
+## Klaviyo
+ 
+Klaviyo is heavily focused on e-commerce and customer lifecycle marketing.
+ 
+Its current Free plan includes:
+ 
+- Up to 250 active profiles
+- 500 email sends per month
+- $5 of mobile messaging
+- Reporting
+- Segmentation
+- Automation
+ 
+Klaviyo integrates closely with customer and purchase data, making it especially relevant for e-commerce brands.
+ 
+Pricing increases as the number of active profiles and message volume increase.
+ 
+## HubSpot
+ 
+HubSpot combines email marketing with:
+ 
+- CRM
+- Forms
+- Sales tools
+- Automation
+- Customer data
+- Reporting
+ 
+Its current Marketing Hub offers a Free tier.
+ 
+Paid tiers can increase substantially as businesses require more advanced automation, reporting, and marketing functionality.
+ 
+HubSpot is often relevant when email is only one part of a larger CRM and sales workflow.
+ 
+# Minimum Entry Setup
+ 
+Email marketing can be started with very little upfront software cost.
+ 
+ 
+| Requirement             | Example                       | Starting cost               |
+| ----------------------- | ----------------------------- | ---------------------------: |
+| Website or landing page | Existing site                 | Already owned possible      |
+| Signup form             | Email platform                | Free options available      |
+| Email platform          | Mailchimp / Klaviyo / HubSpot | Free options available      |
+| Business domain         | Existing domain               | Already owned possible      |
+| Analytics               | Platform reporting            | Included                    |
+| DNS authentication      | Domain settings               | No additional software cost |
+ 
+ 
+A small business can therefore begin building an email list without purchasing an expensive marketing stack.
+ 
+Costs grow primarily with:
+ 
+- Contact count
+- Send volume
+- SMS usage
+- Automation complexity
+- Advanced reporting
+ 
+# Practical Workflow
+ 
+## 1. Define the Goal
+ 
+Decide what email should accomplish.
+ 
+Examples:
+ 
+- Increase repeat purchases
+- Convert free users
+- Drive traffic to content
+- Promote launches
+- Retain customers
+ 
+Do not start by sending newsletters without knowing why the emails exist.
+ 
+## 2. Choose a Platform
+ 
+Consider:
+ 
+- Contact count
+- E-commerce integration
+- Automation
+- CRM requirements
+- Pricing
+- Reporting
+- SMS needs
+ 
+Do not choose a platform only because it has the most features.
+ 
+## 3. Authenticate the Domain
+ 
+Set up:
+ 
+- SPF
+- DKIM
+- DMARC when appropriate
+ 
+Verify the platform's sending-domain configuration before scaling volume.
+ 
+## 4. Create Signup Points
+ 
+Add subscription opportunities to appropriate areas such as:
+ 
+- Homepage
+- Blog
+- Checkout
+- Landing pages
+- Product pages
+ 
+Explain what subscribers will receive.
+ 
+## 5. Build the Welcome Sequence
+ 
+A new subscriber should receive a useful introduction.
+ 
+For example:
+ 
+Email 1 — Welcome
+Email 2 — Best resource or product education
+Email 3 — Customer problem and solution
+Email 4 — Offer or next action
+ 
+The exact sequence depends on the business.
+ 
+## 6. Segment Subscribers
+ 
+Separate major groups such as:
+ 
+- Prospects
+- Customers
+- Active customers
+- Inactive subscribers
+ 
+Avoid sending every message to everyone.
+ 
+## 7. Create a Sending Schedule
+ 
+Decide:
+ 
+- Newsletter frequency
+- Promotional frequency
+- Automation triggers
+ 
+Consistency can help establish expectations.
+ 
+Sending far more frequently than subscribers expect can increase unsubscribes and spam complaints.
+ 
+## 8. Test Before Sending
+ 
+Check:
+ 
+- Subject
+- Links
+- Buttons
+- Images
+- Mobile layout
+- Personalization
+- Unsubscribe
+- Tracking
+ 
+Send test emails to several major email clients if possible.
+ 
+## 9. Send and Monitor
+ 
+Review:
+ 
+- Delivery
+- Clicks
+- Conversions
+- Unsubscribes
+- Spam complaints
+- Revenue
+ 
+Do not judge every campaign from one metric.
+ 
+## 10. Improve Automation
+ 
+Review which automated emails:
+ 
+- Produce revenue
+- Have high drop-off
+- Receive low clicks
+- Generate complaints
+ 
+Update poor-performing sequences over time.
+ 
+# Common Technology Stack
+ 
+A practical email marketing stack may include:
+ 
+- **Email platform:** Mailchimp, Klaviyo, HubSpot, or another ESP
+- **Website:** Shopify, WordPress, Webflow, custom site, or SaaS application
+- **Forms:** Built-in email platform forms or website forms
+- **CRM:** HubSpot or another customer database
+- **Analytics:** Google Analytics and platform reporting
+- **E-commerce:** Shopify or another store platform
+- **Authentication:** SPF, DKIM, DMARC
+- **Deliverability monitoring:** Google Postmaster Tools where relevant
+ 
+A small newsletter may only need an email platform and signup form.
+ 
+A mature e-commerce program may connect the store, customer database, analytics, SMS, product catalog, and behavioral events.
+ 
+# Risks / Things to Know
+ 
+## Sending Without Permission
+ 
+Unwanted email can generate spam complaints and legal problems.
+ 
+Use clear signup and consent processes appropriate to the market.
+ 
+## Buying Email Lists
+ 
+Purchased lists frequently contain people who did not request messages.
+ 
+This can damage sender reputation and deliverability.
+ 
+## Poor Authentication
+ 
+Missing SPF, DKIM, or DMARC configuration can increase authentication and delivery problems.
+ 
+Authentication should be configured before large-scale campaigns.
+ 
+## High Spam Complaints
+ 
+Google currently requires bulk senders to keep spam rates below its threshold.
+ 
+Repeated complaints can damage the sending domain's reputation.
+ 
+## Sending Too Much
+ 
+Increasing volume suddenly can trigger delivery problems.
+ 
+Google recommends gradually increasing volume and sending at a consistent rate.
+ 
+## Ignoring Inactive Subscribers
+ 
+Keeping large numbers of permanently inactive contacts can:
+ 
+- Increase platform costs
+- Reduce engagement
+- Make list metrics less useful
+ 
+Create a re-engagement process and consider removing contacts who no longer want the emails.
+ 
+## Platform Costs Scale with the List
+ 
+Many email platforms charge according to:
+ 
+- Contacts
+- Active profiles
+- Send volume
+ 
+A rapidly growing list can significantly increase monthly software costs.
+ 
+Review pricing before migrating large lists.
+ 
+## Legal Requirements Differ by Country
+ 
+CAN-SPAM applies in the United States, but other countries and regions have different privacy and electronic-marketing laws.
+ 
+Businesses should understand the rules applicable to their recipients.
+ 
+# Frequently Asked Questions
+ 
+## What is email marketing?
+ 
+Email marketing uses email to communicate with subscribers and customers for purposes such as promotion, education, retention, onboarding, and relationship building.
+ 
+## Is email marketing free?
+ 
+It can be started with free email-platform plans.
+ 
+Costs increase as the subscriber list, message volume, automation needs, and feature requirements increase.
+ 
+## Do I need a website?
+ 
+Not strictly, but a website or landing page makes it easier to collect subscribers, explain the offer, and convert email traffic.
+ 
+## Can I buy an email list?
+ 
+It is generally a poor strategy.
+ 
+Purchased lists can create consent, deliverability, platform, and spam-complaint problems.
+ 
+Building a permission-based list is more sustainable.
+ 
+## What is an email sequence?
+ 
+An email sequence is a predefined series of emails sent over time or triggered by user behavior.
+ 
+Examples include welcome, onboarding, abandoned-cart, and re-engagement sequences.
+ 
+## What is an email automation?
+ 
+Automation sends emails based on events or conditions without manually sending each message.
+ 
+Examples include signup, purchase, inactivity, and cart abandonment.
+ 
+## What is email deliverability?
+ 
+Deliverability refers to whether sent messages successfully reach recipients and avoid being rejected or filtered as spam.
+ 
+## What are SPF, DKIM, and DMARC?
+ 
+They are domain-authentication technologies used to verify that messages are authorized and to reduce spoofing and phishing.
+ 
+## Do I need SPF, DKIM, and DMARC?
+ 
+Google currently requires SPF or DKIM for all senders to Gmail accounts and stronger authentication requirements for qualifying bulk senders.
+ 
+Large senders should configure SPF, DKIM, and DMARC correctly.
+ 
+## What counts as a bulk sender in Gmail?
+ 
+Google currently considers a sender sending close to 5,000 or more messages to personal Gmail accounts within a 24-hour period a bulk sender.
+ 
+Messages from the same primary domain count together.
+ 
+## Can I send marketing emails without an unsubscribe link?
+ 
+This can violate platform rules and applicable law.
+ 
+Google requires qualifying bulk marketing senders to provide one-click unsubscribe and a clearly visible unsubscribe link.
+ 
+## Which email marketing tool should I use?
+ 
+The best choice depends on the business.
+ 
+Mailchimp works well for general email marketing, Klaviyo is strongly focused on e-commerce and customer data, while HubSpot is useful when email needs to integrate deeply with CRM and sales workflows.
+ 
+## Is email marketing still effective?
+ 
+Email remains useful because businesses can communicate directly with subscribers and automate lifecycle messages.
+ 
+Results depend on list quality, relevance, offer, deliverability, and execution rather than simply sending more messages.
+ 
+# Sources
+ 
+- [Google — Email Sender Guidelines](https://support.google.com/mail/answer/81126) — Current Gmail sender authentication, spam-rate, DNS, TLS, DMARC, and unsubscribe requirements.
+- [Google — Email Sender Guidelines FAQ](https://support.google.com/mail/answer/14229414) — Current Gmail definition of bulk senders and enforcement details for senders around 5,000 messages per day.
+- [Google — Bulk Email Best Practices](https://support.google.com/mail/answer/10979322) — Official guidance covering consent, unsubscribe, sending frequency, deceptive content, and bulk-email practices.
+- [FTC — Complying with the CAN-SPAM Act](https://www.ftc.gov/media/71413) — Official U.S. guidance for commercial email compliance.
+- [Mailchimp — Marketing Pricing](https://mailchimp.com/pricing/marketing/) — Current Free, Standard, Premium, contact, and email-send pricing information.
+- [Klaviyo — Pricing](https://www.klaviyo.com/pricing) — Current Free plan limits, email sends, active profiles, reporting, segmentation, and messaging allowances.
+- [Klaviyo — How Billing Works](https://help.klaviyo.com/hc/en-us/articles/115000976672) — Official explanation of Klaviyo profile, email, messaging, and product billing.
+- [HubSpot — Marketing Hub](https://www.hubspot.com/products/marketing) — Current Free, Starter, Professional, and Enterprise marketing-platform pricing and email automation features.
+- [HubSpot — Customer Platform Pricing](https://www.hubspot.com/pricing/suite) — Current HubSpot platform pricing and plan structure.