That's a great question! I can definitely understand the want to be able to switch emails templates from editor to the other. I apologize this is not a feature we currently provide. I would be more than happy to pass on your feedback to the appropriate teams and track this request in your account. In the meantime, emails that are in our Second-Generation Editor will remain in this editor. These emails would have to be recreated in our newest Third-Generation editor. Here is an article we have to help with Moving from the Second-Generation Editor to the Third-Generation Editor.
If you decide that you did not want to recreate this email yourself, we do offer an Email Template Design Services. This service helps save times and offers customized, mobile-responsive, email templates to be created in our Third-Generation Editor by a member of our Design Team. You can place in a request for this service through our support by phone , or through the form on our Professional Services page.
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