Automatically Forward Apple iCloud Messages

You can have all your iCloud Mail messages forwarded automatically to another email account.

Automatically forward emails (all)

1. In Mail on iCloud.com, click the Settings button in the Mailboxes list to open the Preferences pane.
2. In the General tab, select “Forward my email to,” then type the forwarding address in the text field.
3. If you don’t want to store a copy of each forwarded message in iCloud, select “Delete messages after forwarding. Keep in mind that storing copies of forwarded messages decreases your available iCloud storage space.
4. Click Done.

You can also create a filter to forward only specific emails to your Parsio Mailbox.

Link: Official guide