Try replacing (Email) with ({name of the column or field where email is listed in your table}) and similarly for (Subject) and (Body).
I’m a noob too but this doc is helpful: https://blog.airtable.com/now-available-button-field/ and here’s a screenshot of the code they use in the gif:

Try replacing (Email) with ({name of the column or field where email is listed in your table}) and similarly for (Subject) and (Body).
I’m a noob too but this doc is helpful: https://blog.airtable.com/now-available-button-field/ and here’s a screenshot of the code they use in the gif:

Welcome to the community, @Pulkit_Agrawal! :grinning_face_with_big_eyes: I believe that @Andy_Bowring is already including those field names. They’re just one-word names, so they don’t require the surrounding curly braces in a formula.
To your question, @Andy_Bowring, you went a bit overboard with the URL encoding.
The email address itself should not be encoded. Only the subsequent items passed—subject, body, etc.—need to be encoded. By encoding the URL, the “@” turns into “%40”, rendering the email address invalid.
Edit: Sorry…I rushed a bit when I saw that encoding issue. Regarding the error, check your quotes. Make sure they’re straight quotes, not styled quotes. Airtable cares which one you use, and will only work with straight (non-styled) quotes in formulas.