Can I route emails sent to one inbox also to others?

It is possible to create so-called Alias inboxes. You can access this feature in the Search icon in the top navigation:

Alias addresses allow you to route incoming emails to several inboxes at the same time. If you connect, for example, three inboxes to an Alias address, all emails sent to this address will show up in the three inboxes.

This feature comes in handy if you have multiple email sources but you want to have one single point of entry into mailparser.io. You can then send all your emails from all sources to one single Alias address and then forward them to specific inboxes which will then parse the content.

This feature works great in combination with inbox conditions. Once you created an Alias address, set it to "Selected Inboxes" which will show you a list of all your inboxes. 

For each inbox you can Select "Activated" then click on "Conditions" and define under which condition this inbox should accept an email. You can add rules like "Only accept emails which have the word XYZ in the subject". This way you can set up a sophisticated email routing based on the content or subject of the emails.