I have my personal mail hosted on a hetzner server using mailinabox. I didn't do anything fancy except whatever mailinabox's default config is.
I have no problem with email deliverability to gmail/outlook. I think the difference is that my emails are two-way communication. I email someone, they email back or vice versa. Not a continuous stream of unreplied emails from my personal server to some gmail address (which does look like spam).
I imagine if you set up a script to reply to these emails from your gmail account with lorem ipsum and then deleted those replies after a few days, your problems will disappear.
I have no problem with email deliverability to gmail/outlook. I think the difference is that my emails are two-way communication. I email someone, they email back or vice versa. Not a continuous stream of unreplied emails from my personal server to some gmail address (which does look like spam).
I imagine if you set up a script to reply to these emails from your gmail account with lorem ipsum and then deleted those replies after a few days, your problems will disappear.