Convert a Lightning Email Template from SML to HML

All Lightning email templates created before Summer ‘18 are SML email templates, even if they don’t have any SML merge fields. All Lightning email templates created in Summer ‘18 and later are HML email templates, even if they don’t have any HML merge fields.

You have several choices.

• If the email template doesn’t have any merge fields, it’s converted to an HML email template when you save it.
• You can continue to use Classic email templates and Lightning email templates created with SML merge fields. You can update and save these email templates without having to remove SML merge fields.
• If you want to enter additional SML fields, do so manually.
  

  Note The merge picker shows HML fields only.
• If you add SML merge fields to an HML email template, you can’t save the template until the SML merge fields are removed.

  In the email composer, you can preview and send an email using an HML email template with SML merge fields. However, the HML merge fields appear as text, not as merged data from Salesforce.

• If you modify an email template so that it has HML merge fields only, and no SML merge fields, it’s converted to an HML email template when you save it.
  

  Note HML email templates can't be converted to SML email templates.

To convert Classic email templates to HML email templates: