Stealth account lockout problem: Solved

Here's a quick one from work -- and no, this isn't leaking any Amazon info, just a solution to what might be a common enough problem with Macs on a Windows-y network.At one point Amazon had an outward facing Exchange server that I was able to point my home Mac to. I was able to read and respond to emails easier than on one of the iOS devices that are also linked to my work account. As time passed that service was discontinued -- it wasn't important enough for me to complain about it.I did what I figured was needed: I opened Mail, went to accounts and deleted the Exchange account it was pointing to. Problem: solved. Right?More time passes. Eventually I have to change my password.From this point on my account was getting continually locked out. This isn't as bad as it might seem since it auto unlocks after a period of time. Maybe it is that bad since it adds a bit of indeterminism to the mix; when I try logging on it either works or it doesn't depending on unknowns that I have no real way of knowing.We chased this with the help desk for a couple of weeks ruling out one thing or another. Eventually the log for Exchange was looked at. My two home machine names were trying to log on.But I took Exchange out of Mail, right?Well, I did, but it was lodged somewhere else:When I added the account to Mail, it also added it to contacts and calendar! Various programs were still trying to use my old credentials to log in to non-email services... not email, but more broadly Exchange.Once I took my account out of the global preferences, my problem vanished!Just something to think about if you ever run into something similar... it always goes back to revisiting assumptions and expectations. If those were right, you wouldn't be debugging a problem in the first place.