NotZed, it’s a fact of usability life that some users will always see what they want (or are conditioned) to see, however hard you try to make them see something else. If it’s only 1 in 10 then let them go and use something they think is better for their job… free software is all about choice, right? If it’s 5 in 10, then try to figure out why they’re not seeing what’s obvious to you because you’ve been working on it every day for the past six months.
FWIW, I actually looked at this dialog a good few times before I saw the Username field too– and I knew it must be there or you wouldn’t be annoyed about it 🙂 My guess is that it’s sometimes being overlooked because the “Server requires authentication” checkbox and the authentication section itself aren’t beside each other. (Paper prototyping is a great way to find out this sort of thing before anything ever hits the screen…)
It’s maybe because there is no text box for the password. Habitually, when I enter my username there is a password text box too. And a user input should be before a default combo box we don’t touch…
Yes, that’s certainly a possibility too… not asking for the password until the first time it’s needed is fairly common behaviour in mail apps these days, but I also found it a little unusual the first couple of times I encountered it.