…but it’s okay if other people don’t mean what they say.
To illustrate: a person who volunteered to script out a libretto translation for supertitles emails you, saying: “This isn’t going to work, I need a literal translation because I can only put up one phrase at a time. How long would it take you to do that and send it over to me?”
They don’t mean: “This is TERRIBLE this is not what I was looking for AT ALL you’re such a BAD PERSON and a DREADFUL professional what were you THINKING!!!?!?!??!?!?!??!” (with exclamation points and question marks ad infinitum, because we all know that person…)
They may instead actually mean: “This is a beautiful translation, but I don’t know how to work with it. Could you please help me?”
So, don’t email them back: “Oh my GODS how could you be so STUPID and not APPRECIATE all of my hard work you’re a blithering MORON!!!!?!??!?!?!?!??!?!??!?!” (also because you don’t want to become that person…)
Instead, write: “The project managers and I agreed that a more poetic, lyrical translation would be best for this concert. I did endeavor, however, to translate phrase by phrase, instead of being completely free with the translation. The ideas in each line should still line up between the French and the English translation. Would you like me to send you a copy of the English with the corresponding French text lined up?”
Now, instead of being a terrible awful person, you are instead a pleasant, helpful correspondent who goes beyond the job description to make everyone’s lives easier. And then, the people you work with are grateful, appreciative, and even more complimentary on your work.
As Wil Wheaton says, don’t be a dick.
(Especially when the other person is a volunteer – they are only being nice! Don’t make them mad.)