Gmail feels like a walled garden. Anecdote: Years ago I owned a one bedroom condo, had a baby, and moved to a larger rented space. We were ~10 emails deep wit

Gmail feels like a walled garden. Anecdote: Years ago I owned a one bedroom condo, had a baby, and moved to a larger rented space. We were ~10 emails deep with a prospective tenant in our old place. I was using fastmail through a private domain (me@mywebsite.ca), the tenant was using gmail. Everything was finalized, and I gave some particulars about how the tenant could pay us. This was enough to be dropped into their spam folder and, except for a chance encounter at the grocery store, the tenant would have believed we had ghosted and missed out on the condo. The silent drop after established back-and-forth is frustrating enough, but the worst part was that we never managed to reestablish email communication. Marking my emails as not-spam, adding me as a contact, etc etc. No future mail from my address to his ever landed in his in-box. I consider myself lucky that my email address was only locally blocked - gmail users in general can still receive email from me.