It is possible that you want to change the contact person (attn) for the estimate.
If you are working on the estimate, you can change the contact details using the pencil icon in the top-left corner. Then use the dropdown to select the right contact person.
Rodeo shows all contact persons added to the client.
If the correct contact person is not listed, it must first be added under contacts.
You can read more about how to add contacts here.
The selected contact will be shown as (attn) on the estimate.
When sending the estimate, you have the option to add multiple billing addresses to the email template.