"Hence POP, or Post Office Protocol, which reigned supreme in
the pre-broadband days when people didn't stay connected to their
mail server all the time. Back in the day, a user would dial up
with a telephone modem, grab their mail with POP, have any mail
they composed offline sent, and then read new mail at their
leisure, connecting again later to send additional messages.
"I just POP-ped down (is it really POP-ped?) a few thousand
messages, and for now I'll just say that moving a complicated heap
of mail in folders down via POP is messy and nearly undoable. And
the mail server in question, at any rate, isn't happy about mass
downloads of mail all at once to the local drive."