Conditional Content on Subject lines and Sender details in the New Editor

Hi ​@Ali-9 

Right now the new Email Designer only supports Conditional Content on in‑email components (text, images, structures), not on the header fields.

More specifically:

• Conditional Content in the new editor is powered by Segmentations and can be applied to content blocks inside the email body (via the Enable conditional content icon).
• It does not currently work on Subject, Preheader, From name, or From email. Those fields remain single‑value per email asset, so you can't drive them off Segmentations the way you could with Dynamic Content in the classic editor.

So today your options for localized subjects/sender details are:

• Continue using tokens (program/lead/company tokens) in those header fields, or
• Create separate email assets per language/variant and route people to the right email via Segmentations/Smart Campaign logic.

This is a known limitation compared to the old editor: Conditional Content in the new Email Designer currently only works for in‑email content blocks, not for header fields like Subject or From. There's no published timeline for adding it to headers yet, so for now the only options are tokens or separate localized email assets; if this is important for you, I'd recommend logging/upvoting an Idea so it's visible as a feature request.

https://experienceleague.adobe.com/en/docs/marketo/using/product-docs/email-marketing/email-designer/conditional-content

https://experienceleague.adobe.com/en/docs/marketo/using/release-notes/previous-releases/2025/release-notes-oct-25