This update simplifies the styling behind message author prefixes in Odoo's Mail app as part of a broader interface cleanup. It should help keep the messaging interface easier to maintain while preserving the existing user experience.

Part of the overall v16 SCSS optimization/restyle, task-2704984

task-2826482

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The mobile mailbox selection screen in Discuss was simplified by replacing custom styling with shared interface classes. This reduces maintenance effort and includes a small visual correction so selected buttons no longer show an unintended outline.

Current SCSS is replaced with global Bootstrap classes, in
order to reduce code lines and to increase performance.

Task-2821469

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The mail message action list styling was simplified as part of a broader visual cleanup for Odoo 16. This helps keep the interface easier to maintain and supports a more consistent user experience without changing core business workflows.

Part of the overall v16 SCSS optimization/restyle, task-2704984

task-2826366

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