Configure Two Domain Emails & add place a website - I have the HTML

I’ve finished designing my site, uploaded the HTML, and now own two separate domains. The last piece I can’t get past is email. I need both domains to send and receive messages reliably—ideally through whichever platform makes sense once you look at the DNS and hosting (G-Suite, Outlook, or a straight-up custom server are all on the table).

Here’s what I’m after:
• Correct MX, SPF, DKIM and DMARC records for each domain so messages land in the inbox, not spam
• One or more working mailboxes per domain (please advise on best naming convention)
• Webmail or third-party client access tested and confirmed
• Guidance on forwarding or aliases; I’m not sure yet if I’ll need them, so a quick walkthrough of options would help

I already have full control of the registrar and hosting panels (cPanel/​DNS manager). As soon as everything is live and a couple of test sends come through clean, we’re done.