Acknowledge the customer's feelings
When you're reading an email from a customer does the image of a toddler having a tantrum sometimes pop into your head? Sometimes the fierceness of our customers feelings can be surprising. For our response to be effective in those situations we need to help the customer get past their feelings and begin thinking. One way to do that is to acknowledge the customer's feelings. When our customers email to express those big, big feelings we need to acknowledge the feelings without necessarily agreeing that those feelings are justified.
For example, if a customer emails your hotel to say that he was disgusted because the tiny bar of soap on the vanity was unwrapped you may think, oh my sir, you need to get a life. Of course, what you really should do is respond and acknowledge the customer's feelings. You might not agree with the customer's feelings, but ignoring those feelings won't make them go away and it may cause the email exchange to go on longer than it should. One reason to acknowledge the customer's feelings.
Source: https://www.linkedin.com/learning/writing-customer-service-emails/acknowledge-the-customer-s-feelings