Emails allows you to import .eml files into Obsidian as markdown using templates.
You first need to download the email as a .eml file. This can normally be done by opening the email in your email client and clicking the Download button.
Once you have the file, run the Import Email command, and select the file.
Emails will import the .eml file and apply your template (or the default template) to it. The output will be inserted under your cursor.