Marketing emails need to be personalized to the reader and filled with interesting graphics. Few people want to read emails that are addressed "Dear Sir/Madam" -- as opposed to their first or last name -- and even fewer people want to read an email that simply gives them a wall of text. Visuals help your recipients quickly understand what the point of the email is.
There are lots of ways to buy an email list, but none of them will actually benefit your campaign. Why? Since the owners of these email addresses didn't explicitly agree to receive content from you, there's no telling how interested they are -- or if they're even a fit for what you have to offer. A bought email list is also in violation of GDPR (we'll talk more about this in just a minute).