How to Use a Custom HTML Email in Mailchimp

Mailchimp is the world's most popular email marketing platform, with over 13 million active users. Its drag-and-drop editor is popular, but it imposes design constraints that many marketers easily work around.

The good news: Mailchimp allows importing custom HTML, either as a reusable template or directly in a campaign. This guide explains both methods and the Mailchimp-specific features you need to know.

1. Workflow: MailBuildr → Mailchimp

1. Design your email in MailBuildr — using an AI prompt or the visual block builder
2. Add Mailchimp Merge Tags — especially *|UNSUB|* in the footer
3. Export the HTML — "Export HTML" button in the MailBuildr editor
4. Import into Mailchimp — as a template or in a campaign
5. Send after validation

2. Method 1: Creating a reusable HTML Template

1. In Mailchimp, go to Content → Templates
2. Click "Create Template"
3. Select "Code your own"
4. Choose "Paste in code" or "Import html"
5. Paste your HTML exported from MailBuildr
6. Click "Save and continue"

3. Method 2: HTML directly in a campaign

1. Create a new Email campaign
2. At the Design step, click "Template"
3. Scroll to "Code your own" and click it
4. Copy-paste your HTML or import a file
5. Continue to the Recipients step

4. Essential Mailchimp Merge Tags

• *|FNAME|* — Contact first name
• *|LNAME|* — Last name
• *|EMAIL|* — Recipient email address
• *|UNSUB|* — Required — Unsubscribe link (text link)
• *|UNSUBSCRIBE_URL|* — Raw unsubscribe URL (for button integration)
• *|LIST:COMPANY|* — Your company name from list settings
• *|LIST:ADDRESS|* — Postal address (also legally required)
• *|CURRENT_YEAR|* — Current year (useful for footer legal text)

5. Preview and test send

1. Mailchimp preview — click "Preview and Test" → "Enter preview mode"
2. Test send — "Send a test email" to your own address
3. Spam test — Mailchimp shows a spam score. Aim below 3.
4. Check merge tags — Mailchimp can simulate values for a given contact

6. Mailchimp-specific best practices

• Image hosting: Mailchimp has built-in image hosting. Upload your images and replace URLs in your HTML.
• Avoid heavy files: Mailchimp recommends less than 100 KB of HTML.
• Link tracking: Mailchimp automatically wraps all your links for tracking.
• Use mc:edit attribute on zones you want to be editable in Mailchimp's editor.

7. FAQ

How many emails can you send with Mailchimp for free?

The free Mailchimp plan includes 1,000 sends per month to a maximum of 500 contacts. Paid plans start at around $13/month. Comparatively, Brevo offers 9,000 emails/month for free with unlimited contacts.

Does Mailchimp modify my HTML on import?

Yes, slightly. Mailchimp may add a legal footer if missing, wrap your links for tracking, and modify some attributes. The HTML exported by MailBuildr is designed to minimize these involuntary modifications.