(I'm in a really bad mood right now, sorry if I'm rude.)"
Phrases like this one should be struck out of the lexicon. If you're in a bad mood when you get an e-mail, WAIT UNTIL YOU'RE IN A BETTER MOOD before replying to the e-mail.
I completely agree with this. It seems like she is using his email as an excuse to act on her bad mood.
Sounds like she had a cruddy day and is taking it out on him, by her own admission.
Also, if I received this email, I would be irritated, too. I would feel like a naughty toddler being scolded by an adult. The whole thing just rubs me the wrong way. Justified or not, she could have found a more tactful way of communicating her wishes: "Hey, there. Happy New Year to you, too!. Nope, no work that I am aware of, but rest assured I will let you know when / if something comes up."
See? Not so hard.