How can I forward all my iCloud emails to a Gmail address?
Solution 1:
In iCloud Mail, click the Action pop-up menu in the sidebar (as in the picture), then choose Preferences.
In the General pane, select Forward my email to, then type the forwarding address in the text field.
If you don’t want to store a copy of each forwarded message in iCloud, you can select: Delete messages after forwarding.
Keep in mind that storing copies of forwarded messages decreases your available iCloud storage space.
At the end clink: Done.