If the mailbox got too big, email would need to be deleted or moved to a local folder on the user's computer.
Note the use of the term "folder". That's an end-user syntactic sugary term, abhorred by anyone who's actually aware of computing technology. The proper term was, is and will always be "directory". The system call primitive is, of course, "opendir(2)", specified by POSIX 1-2001. A manpage states:
The opendir() function opens a directory stream corresponding to the directory name, and returns a pointer to the directory stream. The stream is positioned at the first entry in the directory.
Yes, it's a subtle thing but is calls into question the credibility of the entire piece. The author, Philip Bump, writes about politics for The Fix. He previously wrote for The Wire, the news blog of The Atlantic magazine. He has contributed to The Daily Beast, The Atlantic, The Daily, and the Huffington Post. Philip is based in New York City. That leftist has no clue and obviously suffered a severe bump on his little head.
Apparently, he also worked as a "senior designer" at Adobe Systems (of document layer fame). So, I suspect he probably remembers what opendir() is.
Yes. That is one of my major peeves. You'd be surprised though, at how many windows "administrators" who never use the proper term. Well maybe not. Personally, it annoys the hel out of me.