Afaik one of the parameters that is used to grade remote servers, is how much legitimate mail it has sent recently. This causes small servers to with few emails sent in total each day/week to score higher on spam evaluation.

I've read documentation on newsletter services, that if you elect to use a dedicated IP address for your outbound emails, it needs to be "warmed up" over a few weeks with smaller groups of recipients, and that you need to keep a persistent high volume once it's warm. This helps keep your SMTP host "well-known", which is somehow more trustworthy.

Of course newsletters and personal email are not the same, but they unfortunately go through the same spam-filters.

I hosted for years and got tired of fighting with the big players servers.. then I realized 95% of every email and sent or received was going to or from a person's Gmail account and gave up.

I have been using https://www.scaleway.com/fr/transactional-email-tem/ from scaleway. They have a 300 emails/month free allowance which is enough for me. Haven't had any delivery issue, but haven't tested extensively either.

it's known that google doesn't want you to use email, they want you to use gmail. same as how all those fucks co-opt standard protocols (XMPP, ActivityPub, etc.) and then defederate it and make it their own walled, proprietary thing.

I ran a slew of geo-dispersed mail servers for a decade+; not really spam as it's willing recipients but essentially not that far from it, either. also fully compliant, experimenting with voodoo-adjacent tips for improving deliverability (none of them work). so glad to be out of that racket.

anyhoo, you can utilise mailchimp/sendinblue/etc as they have a direct pipe into gmail/outlook infra and are not subject to any of those harassment tactics, which is basically payola. the prices last time I was involved with checking things weren't that much better (worse in fact, if you add the costs of running all that shit) than transferring everything to gmail and friends, which is their ultimate goal.

https://tools.sendmarc.com/ Is a good start. Listen back through the security now eps where he’s setting up his own email list with his own email server.