The HTML mail root has contain: content, which clips anything that
overflows it, and nothing let it scroll. Mail built to a fixed width that
cannot shrink (a min-width table, a nowrap cell, a nested fixed layout)
was cut off at the pane's edge, with no way to reach the rest. That is
worst on a phone, where most marketing mail is wider than the screen.
The root now scrolls sideways (overflow-x: auto). Vertical overflow stays
clipped, as containment already made it, so no second scrollbar appears.
Mail that fits shows no scrollbar.
Verified in the browser on the mock with a 1200px min-width table in an
871px pane: on main the right 345px were clipped and unreachable; with
this change the root scrolls and the last cell comes into view. Plain
fixed-width tables were already squeezed to fit by max-width: 100%, and
still are. Not tried by touch on a real phone. No new strings.
Fixes#24. Reported by @mbjboon82.
jcoffey-dev