How reliable is it to self host SimpleLogin, AnonAddy (addy), etc?

I have a private @gmail and a business @company.com (also via gmail), which I heavily rely on. Due to a recent data-leak somewhere, I'm now receiving unstoppable spam on my @gmail, and decided to set up a new account on proton and ditch @gmsil in favor of @example.com. I came across SimpleLogin, and thought that I could use that instead of protons custom domain feature for both @company.com and @example.com

Since I also host some stuff myself, I went through the self-hosting process of SimpleLogin, which was a pita dealing with postfix. But now, everything is running fine and I can send/receive @exampke.com emails, which I tested with @gmail and @company.com (gmail).

Even though it was a nice learning experience, I'm starting to wonder whether my setup is future proof and reliable, especially when it comes to spam. I really don't want my @company.com mails to land in customers spam folders.

So my question is, how reliable is a self hosted email-forwarding solution, and how does it compare with a self-hosted mail service. Like, are these two equal in terms when it comes to precautions etc?