Some settings have been renamed or relocated in the new UI. Below, you'll find a guide showing where to find them now.
Sender and Reply Addresses can now be found under Account Settings > Senders
Tracking Domains and Email Authentication can now be found under Account Settings > Domains
Push configurations can now be found under Account Settings > Connected apps
Boilerplates and Skins can be found under Main Menu > Content
Link Categories and Snippets can be found under Main Menu > Content
Recipient Attributes and DataDoc Types can be found under Settings > Contact data
Data Retention can be found under Settings > Account
Opt-in / Opt-out / Account Unsubscribe can be found under Settings > Subscriptions
Users and Permissions can be found under Main Menu > Users