When validation SMTP configuration in Administration/Server...
Clicking the "Test SMTP settings" button, enter email address and click "Validate". The dialog disappears and there is no indication that anything is happening, though there is a request in progress. If successful or failure sometime later a dialog is displayed to inform the user.
This is confusing and unexpected.
The validate dialog should stick around with a wait mask over it until the request completes at which time the dialog can be dismissed and replaced by the success/failure dialog.