<p>I once had a professor chastise me for being too polite in an email! I wrote something like:
"ProfessorName,
I realize you are probably very busy and so I apologize for bothering you, but... [insert question here]... Once again, thank you for your time, and I'm sorry for bugging you!</p>
<p>Sincerely,
MyName"</p>
<p>The professor wrote me back and said they were glad to hear from me, but that I "simply have to (emphasis in the original) stop apologizing for emailing" them.</p>
<p>It kind of threw me for a loop, I'll admit!</p>