Outlook exchange

We recently purchased a company and added them to our AD/Exchange.
However, they have automated emails coming from vendors and solutions providers that we need to forward to their new Exchange account.
We will eventually, move all vendor / auto emails to our company email but we need to derive this list first without losing current function.

Example:    Cloud CRM emails bill to accounting jsmith@boughtcompany.com we need it to go to John.smith@purchasingcompany.com