When I email a quote from Quickbooks, the email is received in plain text, and not with the actual quote template. How do we fix this?

Let me share information about quote templates in the QuickBooks Online (QBO), service.

In QuickBooks, there are two options to send the quote either in Plain text or in an Online invoice as it has the same view as when a quote has been emailed. However, the custom form style you created will only reflect in the PDF file. Also, please ensure to tick the PDF attached option and download the file to view the email from your customers.

You can follow these steps to check it:

1. Go to the Gear icon and select Custom form styles.
2. Locate the estimate template you're using and click Edit.
3. From the Emails tab, make sure to check the PDF Attached. You can also select either the text is in Full details or Summarized details.
4. Click Done to save it.

Once done, you can send a sample quote to yourself to make sure everything's fine. You can also check this link for more details: Customise invoices, estimates, and sales receipts in QuickBooks Online.

You can comment below if you have other questions about managing templates in QBO. I'll be sure to help you.