Why do I have to confirm the order immediately?

This ensures the customer receives confirmation of delivery, without which they cannot plan their workshop operations. 
If you as supplier, cancel the order early, the customer can still react and procure the necessary spare parts from other source. ClaimParts as business partner is obligated to share reliable order information.

What exactly I have to do, I am unable to fulfil the order precisely?
For example, the ordered item no longer matches the original description in the listing. In this case, please contact us via corresponding link in our email and explain in detail your proposed solution. 
We will discus your proposal with our customer and come back to you shortly thereafter.
How can I change the recipient of this order confirmation email within our organization?
Simply send us please an email with the exact details of the new recipient. 
Please note that the recipient's address must include your company name and may not be used by external parties.
Unfortunately, I am unable to supply the ordered parts after all; however, we do have alternatives.
How should I proceed now?
Please use the corresponding link in the email to submit information regarding your alternative.
We will discus your proposal with our customer and come back to you shortly thereafter.