(sorry in advance if this has been posted before)
So, after having some issues with our hosting provider I decided to move all of the company e-mails to Google Apps. Most of my coworkers access their email with Outlook setup to use POP3 to retrieve the messages and with the option to leave a copy of the message on the server activated, so that if they ever need to check a message and are not in the office they can just go to the Gmail website and everything is there. So it's all pretty standard so far.
After about a day or two one of my coworkers who uses the same e-mail account on two computers complained that the messages where just being downloaded to either one of the computers. I double checked and both computers had the "leave message in server" option activated and the messages still showed up on the Gmail website meaning that they where still on the server. After searching for a bit i find a Gmail support article saying that in order to download messages on more than one client you've to use the recent mode, that means adding "recent:" to your username so myemail@gmail.com becomes recent:myemail@gmail.com. It's a bit odd but an easy fix, which solved the problem. Two minutes later my coworker calls me again, this time his sent messages where showing up his inbox. I check his account on the Gmail website and yes Gmail was moving all his sent messages to the inbox. I search that Gmail support again and find that the solution is to... wait for it... disable recent mod. So if you want to check your e-mail on more than one computer using POP3 Gmail stops caring about folders and puts everything in the inbox. Notice that nowhere on the support article that instruct you to use recent mode does it say anything about this sort of side effects.
You can work around the problem by either using IMAP or by setting filters on all the clients (setting filters on the Gmail website doesn't work) to automatically move all messages from "me" to the outbox, which I now have to do on 30+ computers (yay).
I also found out that apparently, first Gmail doesn't follow the POP spec completely, second it doesn't use any folders to store the messages, all the messages are in the same place but are labeled as either received or sent (or whatever), and third this issue is caused by the stupid conversation view that Google uses but disabling it doesn't work.
Finally I just now realized that there is no way to contact anyone at Google/Gmail when you've an issue, theres no support e-mail or phone number (unless you're a paying costumer). The only option is to post on the Gmail support forums but it has so many new topics per minute that they all end up getting unanswered. So worst support ever!
I don't get why they won't just follow the POP spec like every other e-mail provider, there's no need to keep trying to reinvent the wheel specially not when it has worked as intended for years!