I don’t agree with this hard split between SPAs and MPAs anymore (ie. SPAs for apps, MPAs for websites/content). In my opinion SPAs are simply a progressive enhancement for MPAs which allow even faster page navigation. All frameworks now come with SSR solutions and if a website still requires JS to show content that’s a skill issue.
Looking at Astro the line between SPA/MPA is getting really blurry. Just slap a View Transition element on your page and you got a MPA which acts like a SPA when JS is enabled.
Use a postfix satellite setup. Requires minimal config and provides queues/retries/etc.
https://www.lunanode.com/guides/postfix_smtp_secure