Coding your own email

Write or paste HTML for a campaign, including Mailchimp designs.

Updated October 13, 2026
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Choose Code your own when you create a campaign to start from a blank template or paste HTML. You can also add a Custom HTML block to a canvas campaign, or use Switch to code to turn a canvas campaign into HTML. Switching to code can't be undone.

What's allowed

Scripts, forms, and event handlers are removed, since email apps block them anyway. Keep the email under about 100 KB: Gmail clips longer emails, and BrightSite warns you when you're over.

Every campaign needs an unsubscribe link and your postal address. If your HTML doesn't include both, BrightSite adds its standard footer.

Mailchimp merge tags

Paste a Mailchimp design and its common merge tags are converted, including *|FNAME|*, *|LNAME|*, *|EMAIL|*, *|UNSUB|*, *|CURRENT_YEAR|*, and the list name and address tags. Archive links and preview-text tags are removed. Tags BrightSite doesn't know, such as conditionals, stay in place and are flagged in the checklist before you send.

Still stuck? Ask Lumi inside the app, or send us a note and a person will answer.