Almost always the e-mail is much tamer when I read it than it was in the mind of the nervous-nellie author who sent it to me. Sometimes the note is neutral, completely harmless. Other times it has a little bit of what I call "New York cheddar" to it, but nothing to worry about (New Yorkers can snap at each other when they're happy, let alone when they're not... it is getting better, but unnecessary snippiness is still their collective worst habit). Some of my authors have over-interpreted a simple "No," or "I don't think so," as "Go away and never come back, I'm canceling your contract you worthless excuse for an academic professional."
For the most part, everyone got up this morning thinking about themselves, not you or me. Most e-mails are just language, and the typical professional is careful not to put genuine anger in writing. Even if there was a major issue between you and your editor, you'd hear about it in a different way than casual e-mail.
Authors will continue to send me these e-mails, and I'm always happy to read them and try to help if I can. But your editor is probably not angry at you, and you won't lose your book deal just because you asked questions about it, even if you do get a sharp taste of New York cheddar in return.