My toolbar icons have disappeared!

The fix is to-right click on MailCOPA email program button on the taskbar, and select Restore Default Toolbar Layout.

Alternatively, left-click on the MailCOPA system menu (you'll find the system menu at the extreme top left of the MailCOPA main window, on the 'envelope' icon), and select Restore Default Toolbar Layout.

  MailCOPA System Menu