Professor X introduces professor Y to me. Should I CC prof X when emailing prof Y? [duplicate]

Question

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• Professor cc to other professors when I ask about the PhD student vacancy. Should I answer as a group or to individuals? 2 answers

I email to prof X to ask about a PhD student vacancy. He refuses because of his retirement, but kindly introducing prof Y to me. When emailing to prof Y, should I CC prof X?

I do this because at the end of the letter he says that he wants me to get him informed of my work. But more importantly, even without this saying, I think CC to someone when they has introduced me to another person is a good etiquette. It shows that I'm transparent.

But what if they are not really close? They may know each other through the work of each other, but hasn't had any conversation? Would this make things become awkward? And if he didn't say anything about informing him, would CC him simply annoying him?

_{While you can say that this question is a continue of my previous one, the names have been rearranged completely. For the sake of your understanding, please assume that the two questions have no relation to each other.}

Answer 1

I work with many professors worldwide. I believe that its always good to CC the professor who had introduced you, (avoid only if he is not interested in you to know). Once you are involved with the professor and do some work with him, you are free to communicate independently. Also do not forget to thank him/her for looking forward an opportunity for you.