Clearly you’ve never had to do tech support for people that inadvertently chose POP3 because in many systems it’s still the default selection, along with the default behavior of deleting mails from the server as you fetch them.

What do you mean the only copy of all my mail is in some bizarro mail client specific proprietary database? Why can’t I also read my mail on my phone? I dropped my laptop in the toilet and now my mail is gone. Isn’t it on the server? Why can’t I use folders? Don’t you have backups?

No, your mail is gone, because you used a protocol designed for the 90s. It’s a great idea if you have a mail account with 10mb quota and you download your mail to a fixed, reliable workstation and you don’t mind if you lose it all if the disk crashes, it doesn’t happen that often. Not hardly as often as laptops getting stolen, Windows breaking itself and phones going bust.

I’m not sure why I need to have personal problems with your pet protocol to have an opinion on it, especially on one that stinks as much as POP3. It’s obsolete.

I have an iMac, a MacBook Pro, an iPad, and an iPhone, and I want to be able to access my email from any of them. POP3 is simply not designed to handle that situation gracefully. If a POP3 client is set to download email and delete it from the server, then the messages get "stuck" on whatever client happened to download it first; if it's set to keep copies of the emails on the server, then it pretty much becomes IMAP. Except stupider, since POP3 doesn't treat "downloaded" and "read" as separate concepts.

While I suspect I'm relatively uncommon in having four devices that I want to be in sync, wanting two or three devices -- computer, phone, and possibly work computer -- to be in sync probably isn't very uncommon at all.