I would need some advice about the customs of answering with a "thank you" message to someone who forwarded my mail to a colleague.
To give you more context, I was contacting this person for the first time to ask him some advice. He answered that he could not help me, but copied in a colleague who could help me.
Now my question is: should I say thank you to the first person, or wait for the second to answer? Should I answer the first person, but not including the second person in the mail?
Thanks for your help, I am lost with the business codes (and my desire of avoiding spamming people)