Sometimes an application treats a situation as an error when the situation is, in fact, completely normal.
For a good example of a poor user experience, consider Microsoft Outlook’s support for the IMAP mail protocol. The vast majority of consumers use the POP protocol to get email at home, which generally forces them to keep all their mail on one machine at home. IMAP, in contrast, lets you keep all your email on the server, where you can get to it from work, home and on the road. Most email clients -- including those found on cell phones -- support IMAP. Upon hearing of these wonders, most people will ask why IMAP isn't used more often.
While large portions of Microsoft Outlook are very well designed, there’s no escaping the fact that the Office team cares first and foremost about the enterprise market. Large enterprises have more money than you do. They use Exchange, and Outlook's support for Exchange is fantastic.
People who use Outlook outside of an enterprise struggle along with support for POP mail that hasn't improved appreciably in years. While POP isn’t great, at least Outlook's POP driver is reasonably solid. Outlook's IMAP driver, on the other hand, appears to have been left for dead in the jungle, where it was raised by apes.
Among its many deficiencies, the driver can’t properly cope if you use two different machines (say, at home and at the office) to check your email. This scenario is one of the reasons for IMAP’s existence, and most IMAP clients handle this situation gracefully: if they see another client is checking the mailbox, they wait for a while then try again. If you try to use Outlook this way, however, the IMAP driver throws up the following error:
Your IMAP server has closed the connection. This may occur if you have left the connection idle for too long.
Not only is this message a poor indication of what's actually going on, Outlook displays this message every few minutes until you shut down one of the two Outlook clients trying to reach the mailbox. Outlook even displays this dialog even if Outlook is already displaying another instance of the same dialog. This is insane. I can come home from a day of work and see, literally, a hundred of such errors sitting on the screen.
Somewhere, deep down in the IMAP driver, there's probably a core function that checks for new mail. It's a sure bet that if this function is unable to check for new mail -- if, say, another email client is already checking the same mailbox -- this function returns an error. The function does this not because there’s anything really wrong, but because the function doesn’t have any other way of communicating what’s going on. The developer who wrote the calling function assumed that any error result is a real error, so they wrote the calling function to punt things off to a general purpose error handler that displays a generic error message. The limited forms of expression in code have completely warped the top-level user experience.
That explains why the error dialog got into the product, but why did it stay? Clearly the simplest reason is that none of Outlook’s developers use the product’s IMAP driver themselves. The above error is exactly the kind of thing a developer will kill in five minutes if it's in the way of them doing their own work. It's reasonable to assume that the reason no Outlook developers use IMAP is because they rely primarily on Microsoft-supplied Exchange accounts for email at work. The rest of the world suffers at home because of this.
I use so many of Outlook’s PIM features that I could never go back to a pure email client, but if all you need is mail, I’d encourage you to try Mozilla Thunderbird, which has excellent IMAP support.