Apple mail client with iCloud sync for settings

Hello! I'm looking for a mail client for macOS, iPadOS and iOS. I care about the functionality of synchronizing the settings of this client. I want to have signatures and default font size synchronization. I really like the native Apple Mail client, but unfortunately it does not offer such functionalities at the moment. The application can be paid or free, as long as it has a One-Time Payment instead of monthly or annual subscriptions. Thank you for your help!