What happens upon adding a new reply-to email address in Xero?

When a new reply-to email address is added in Xero, a verification email is sent to that address to confirm the change. This step is crucial for ensuring the validity of the email address and to prevent any potential issues with miscommunication. The requirement for verification helps maintain the integrity of communication channels used in Xero, providing a safeguard against errors and ensuring that notifications sent to the new address are indeed being delivered to the right recipient. Only after the email address is verified will it be fully functional for correspondence related to the Xero account.

In contrast, some of the other options imply that the email address would be active without proper validation or that it would automatically notify customers or that it cannot be changed after immediate activation, which is not the case in Xero's operational procedures. The verification process is a critical step that must be followed for security and accuracy.