When e-mails are imported into DTPO, they can be viewed either as QuickLook or as Alternative View. In the former the font size is set by the OS.
In the latter, the rendering is done by DT. The user can zoom in/out using the toolbar buttons or menu commands.
But these zoom levels are not persistent (‘sticky’) – that is, if you zoom into one e-mail, then move to another one, then move back, the zoom level gets reset every time.
This is annoying because the default font size used in the Alternative View is smaller than I would like. Zoom is useful – and DT should remember the setting, and keep it the way it is.
I note that DT already does this for RTF documents, where the zoom level sticks when you change between documents. I’d love to see the same behavior for e-mails.