We are trying to email a list of our clients through campaigns, but our emails look like marketing emails because of empty space on left and right of the content. It doesn't look like a natural email. How can we solve this issue?

We tried using pain text email which worked but then we can't add links (mostly we need to do that to our linkedin profiles, imdb profiles etc in our signature) and putting a plain url there doesn't look professional. We need to be able to send emails that actually look like personalized emails (we are fine with the unsubscribe buttons and the footer showing up) with the usual professional stuff around it.

Is there a solution to this issue?