I host my family & friends email server for about a half dozen domains for the last 20 years using postfix with courier imap. Once every 5 years, Gmail doesn’t

I host my family & friends email server for about a half dozen domains for the last 20 years using postfix with courier imap. Once every 5 years, Gmail doesn’t like something and starts sending my emails to spam but it resolves by itself in 2 weeks ;) Otherwise, the only maintenance is OS upgrades every 6 months or so.