Yes, you can duplicate a complete inbox including all parsing rules, file downloads, and webhook settings. You will find this function on the inbox overview page right after logging in to your account. For each inbox, you'll see a little duplicate icon when you hover with your mouse over the inbox.
Duplicating an inbox will copy all email parsing rules, all settings and all dispatcher configurations to the new inbox. Typically this means that you are all set and that you just need to forward emails to your new inbox. However, you will probably want to change is the target URL of the webhook dispatchers if you are using this feature.