Preview Mode is a feature found in OnMail that displays your promotional email and news in a more modern, visual format than traditional email clients. Clear through your inbox in a glance! To enable/disable, follow the steps below.
On desktop, Preview Mode is on by default. To toggle it ON or OFF, tap the button in the upper right corner of your Split Inbox that says Preview. Your emails will now be in List Mode. To change it back, tap the button again (which is now titled List.)
On desktop, Preview Mode is on by default. To toggle it ON or OFF, tap on your OnMail avatar → Settings → Split Inboxes. Select the Split Inbox you’d like to change the view for, and tap the view you’d prefer (List or Preview.)