The new Marketo Engage Email Designer, initially limited upon its February release (see our initial review), has evolved with steady improvements. The most significant uplift for Jeto clients to use the new editor is the ability to create and edit Marketo Email Templates easily from a drag & drop interface – which removes the dependency and reduces the need for custom (and costly) template coding.
The good news is: while some Marketo API bugs and limitations remain, we are confident in our ability to support emails sourced from the new editor in Jeto. At this point we cannot confirm if module deletion\controls will be in scope with the initial release, but our team will keep working on solutions to control Fragments in future releases.
The upcoming addition of REST API support (API support for the new email editor is tentatively planned for Q2 2026) will be a crucial milestone, but despite its not officially supported our team had the opportunity to test its compatibility with Jeto Preview function. Here are some of our key findings.
First, here are highlights of the major improvements to the editor since its release.
- February 2025
Initial launch of the drag-and-drop designer with fragments and content locking. Initial limitations included a requirement for Adobe IMS and limited program support (Email only). The API was also not publicly exposed. - March 2025
The designer became available for use in Engagement, Default, and Event Programs, expanding its core usability. - April 2025
Improved asset management was added, allowing users to move emails between programs and delete programs containing new designer emails. - May 2025
Enabled cloning of new designer emails, enhanced personalization with all standard Marketo tokens, and integrated with Adobe GenStudio for generative AI content creation (pad add-on). - July 2025
Introduced “Conditional Content” for dynamic email personalization, critical API infrastructure improvements add the ability custom CSS was introduced, gives users more control over design, bridging the gap between a pure WYSIWYG tool and the full code-based control of the classic editor. - August 2025
Significant bug fixes and performance enhancements were released, including faster email preview load times and a fix for template rendering and content locking issues.
- September 2025
Introduced new REST API endpoints specifically for the new designer, enabling programmatic creation and management of emails. The scripting language for Conditional Content was also switched back from Handlebars to Velocity, a more familiar language for Marketo users.
Throughout the releases, the documentation has been improved including a new Experience League article with Feature Comparison – Old editor vs New Designer and an updated Email Designer Knowledge Base.
Our Experiments
Our approach for testing was simple:
Step 1- Build Marketo program template with new emails
1 Build a new Email Template from the library
2 Create a test program
3 Build 2 emails
a) one from a template
b) one directly from the email editor (no template)
4 Tokenize the program and emails
Step 2- Create a Launcher and a Campaign from the new Program
1 Resync our Jeto instance (to fetch the new program)
2 Create a new Launcher and generate the preview
3 Create a campaign and
a) Preview all assets
b) Edit content (including 1 field for each type, including images)
c) Preview changes
d) Send Sample
e) Submit & observe cloned program
f) Execute test campaign from Marketo
Test Results
API Bug & Workaround
Right out of the gate, we uncovered a bug with Marketo API where the “Browse Emails” endpoint does not return the values for the email Header information (Subject, From, Reply, Preheader etc.). This bug has been reported and we hope it will get fixed soon.
Edit Content, Generate Previews, Send Sample
Once we properly handled the API errors, editing the content from the Jeto form was easy and worked as expected for all token types, generating real-time previews. Sending email samples also worked as expected.
Edit Modules Not Yet Supported
The control of email modules surfaced as a significant gap. As per the Feature Comparison – Old editor vs New Designer documentation, Modules do not exist in the new email designed. Given Marketo Engage does not yet support a public API for email fragments, we had to put our testing of the edit modules function in the new designer in the “maybe later” bucket for now.
Campaign Processing (and Program Clone)
The program was successfully cloned, carrying over the new emails, structure, and values populated by Jeto.
User Interface & User Experience
Generally speaking, the UI gives an amazing level of control over the email editing functions. We loved:
– AI generation: we love testing AI everywhere – and generating email content from prompts is a great use of AI and such a blast to experiment with.
– The new right side panel to control email properties.
– The left side panel with editing controls and new widgets for navigation tree, links, fragments and direct access to assets.
But It Also Presented Some Usability Challenges
– The usual ”right click” contextual menu option shortcuts are gone (or not yet available) creating an inconsistency vs all other Marketo objects.
– Editing an email still required too much digging (click 1 on the email, click 2 on the not so evident “Edit email content” button, click again (3) to confirm the “Create a draft action” , and a final click (4) to select the editable area). Not a deal breaker but not a great experience either.
– The dual “edit” VS “edit content” UX (likely required for performance optimization), where some frequently used menus would benefit a 1st level action as opposed to nested under sub-sections or sub-menus, like editing, moving, cloning and deleting emails.
Conclusions & Next Steps
Six months post-launch, the new Marketo Email Designer has evolved into a robust, production-ready tool. Significant advancements, including conditional content, custom CSS, and improved API infrastructure (although not yet officially supported), have largely shortened the gap with the classic editor, particularly benefiting organizations embracing new template editing and customization.
While limitations such as the inability to migrate older templates, lack of A/B testing, and residual API development persist, we remain optimistic. Jeto anticipates supporting asset previews for the new designer (excluding module controls) in Q1 2026, alongside the official release of the Editor’s API which is mandatory for Jeto Preview and Modules editing functions.
