The ability to add in custom HTML is great. We are using MJML to generate our wonderfully cross platform and responsive email code that works on Act-On, Salesforce, Hubspot, Active Campaign, and lead liaison. The way it supports MSO (Outlook) is it included fixes in the form of HTML comment tags <!--[if mso]> and others like it. The problem here is that Zoho is removing code and breaking formatting after saving.

If i am adding custom HTML, i expect it to NOT remove anything from what i explicitly added in the editor. That is defeating the purpose adding custom code. The email will look fine in the preview, and most email clients, but it breaks very badly in Outlook. Keep in mind this is code that was already thoroughly tested in 60 email clients using a litmus test. if i then take the malformed code from the Zoho editor and test it again, it shows broken in Outlook.