I also self host email and so far haven’t had any problems. Initial setup was annoying but it’s required zero effort this past few years, and I don’t think my emails land in spam folders. Maybe I can help?

Shoot me a message at test-message-lawrenceOfSuburbia@mspencer.net (which I’ll delete after it gets a message, for obvious reasons) and I’ll take a look. (I misspelled the name, I apologize, no insult intended)

Honestly I think I’ve received 10 spam messages in the last four years, and five have been from gmail addresses (Best Buy invoice spam) in the past two months. I submit each one to support.google.com/mail/contact/abuse and hopefully it helps.