I hope you’re doing well!
is OK-ish,
but it still usually goes
after Hi Alex or whatnot.
All recommendations from your link are quite useful
except:
-
Good morning/evening/afternoon ... you never know when they will read your email
-I’m
reaching out about…
yuck ((
reach out
This has become the new cliché for yuppie types or any pseudo-intellectual types or just idiots that think it sounds special. It is simply just another way of saying: contact, call, speak to, notify, etc. It really sounds faggy and flags the speaker as being self conscious about how they sound to their peers. You also have to wonder who they think they're impressing when they speak like they have an Emily Post book on etiquette shoved up their ass.
in general, just use common sense,
western common sense that is, which is often different from ours )