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- Open Outlook app.
- Create a new email.
- Go to your email HTML in the browser and select all elements (Cmd + A). Copy them. (Cmd + C)
- In Outlook, paste your email layout. Some elements may look weird now, but fine after you send the email.
- Send yourself a test email and view on desktop and mobile.
- Outlook can mess with the spacing and width of elements, so you may find you need to remove elements that are messing up the layout or are not filling up the full width.
- When finished testing and editing the template, create a new email, paste in the email layout and go to File > Save as Template
- Send the template file as an attachment.