How to embed a link to an email?

1. Drag & Drop

If you are using an email client app like Apple's Mail, Airmail, or others, you can drag & drop the email directly into NotePlan:

If you just see the title of the email, make sure you are dragging the message and not the complete email thread:

2. Copy & Paste the URL

If you are using a web client like Gmail, you can copy & paste the URL of the email:

You might have to change your view settings in Gmail, so you see a single email in fullscreen like in the screenshot above by choosing "No Split" for the Inbox preferences or click the top right on the following arrow button when you are in your inbox (and not currently reading an email):

When you paste the link into NotePlan, it won't fetch the subject of the email. But you can move the cursor into the title field of the pasted link with your keyboard arrow buttons and just change it to something more meaningful: