The different types of Email templates are listed in the below table:-
Text All users can create or change this template
HTML with letterhead Only Administrators and users having “Edit HTML Templates” permissions can create this template based on a letterhead.
Custom HTML Administrators and users having “Edit HTML Templates” permissions can create this template without the need of a letterhead
Visualforce Only administrators and developers can create this template. Advanced functionalities like merging data from multiple records is available only in this template
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