How to change account display name in apple mail / iOS and iPadOS

Greetings caanan_r,

We understand that you're looking to change the account description for your iCloud email on iOS and iPadOS.

For the iCloud email account that is attached to the iCloud account signed in to Settings > your name, the description of the account cannot be changed. You can view the different options for that account in Settings > your name > iCloud and then scroll to the bottom and tap on Mail. 

Leaving feedback via Apple's product feedback site would be a good option, to let them know what changes would make things easier for you. Product Feedback

Thanks.