No, that isn't it. Thought it was images, but it isn't. It is actually text that is not showing up.
Here is a sample of the raw source:
Content-Type: multipart/alternative; boundary="0000000000002f1a610599118cd5"
X-MANTSH: 1TEIXWV4bG1oaGkNHB1BeSF8aHBgYHhoaGxEKTEMXGx0EGx0YBBkfBBgSEBseGh8
aEQpM....
--0000000000002f1a610599118cd5
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable...
And this is the text that appears as only 2 question marks for the whole paragraph:
Hi, Jeff,
As we spoke about receiving PayPal notifications, could you please add my
other email address, ...@gmail.com. Is it possible for you to tell
me who else receives the notifications from PayPal? I know Jan does.
So apparently text from several sources like UPS is now not being displayed in Apple Mail.