In my old organization, internal emails (same domain, internally sent) were regularly classified as spam if the UA wasn't outlook. "Clutter" added another circle of hell, as not only you had to explain "check your junk folder" but also "check your clutter folder".
I attributed this to the sheer incompetence of the local admins. The same organization later switched to O365, and the problem remained unchanged.
I attributed this to the sheer incompetence of the local admins. The same organization later switched to O365, and the problem remained unchanged.