Almost all of the "profesional" interactions outside of work I used to have over email are now in text: contractors, financial advisors, realtor. For those I pretty much use the same format as email, including subject, salutation, and "Regards, Symbian" at the end. If I text socially, I try to do a quick spell check, but use emojis, shortcuts, less interpunction. Mostly agree with that article, and I am old.