Using Outlook for Android in business environments for email and scheduling
Dear BH1992,
Welcome to Microsoft Community.
I understand that you cannot find the gear icon in Outlook.com to delete the forwarding rules.
I am happy to help you. To find the gear icon, you need to use a PC browser to enter the page https://outlook.live.com/mail/0/ **** and you can see the gear icon in the upper right corner of the page.
This is due to the limitations of mobile browser, the default is to display the mobile version of the web page, so some features have been simplified, and you need to enter the PC browser to see the web page with complete functions.
I hope my reply can be helpful to you.
Best Regards,
Jason.YA - MSFT | Microsoft Community Support Specialist