I have a custom domain email address on Zoho and suffer constantly from delivery issues. Sometimes my emails go into spam filters, sometimes they go into a bla

I have a custom domain email address on Zoho and suffer constantly from delivery issues. Sometimes my emails go into spam filters, sometimes they go into a black hole. It’s a huge PITA and I am tempted to either move providers (maybe it’s Zoho’s fault) or just stop using my custom domain (maybe it’s not Zoho’s fault).