Hey @zzleki, it does look like you have duplicate DNS records for your domain. Have you already looked through this Support Guide about how to set up DNS on Netlify? [Support Guide] DNS Quick Start - How to set up DNS
Additionally, it does sound like you can use nodemailer with Netlify, but there will be some additional steps to set it up and you will need to use Functions on Netlify. Here’s a post with some details about how you can configure this: Netlify function for sending mail with nodemailer doesn't work in production - #9 by coelmay
Please let us know if that helps!