Question: Losing Mail messages
I have a new iPhone 7+; I received it yesterday. Since then, some (but NOT all) messages that I receive on Mail appear for 5 seconds and then evaporate before I can open / read them. I can see the sender, the subject, and two lines of the text. Then they are gone.
This occurs whether I attempt to view them on my iPhone, Mail (on my computer), Mail on my iPad, or Apple Mail (on my browser). All messages are going to my Mac.com e-mail address.
Does anyone else experience the problem? It (obviously) is frustrating because I might be losing some important messages of which I am unaware.
macOS High Sierra (10.13.1), 15", 1.83 GHz Intel Core Duo