Good day to you Hawaiiclare,
We're understanding you to say that when accessing the native Mail app on your iPhone, you see a white screen that states, 'No Email Selected'. You stated you are seeing emails being sent from your iPhone because you see the number of emails increasing.
We have a few steps you can take.
If you haven't already, please also restart your iPhone. This is simply going to refresh the software and connections. Restart your iPhone. Then, after the restart relaunch the Mail app. From the screen showing that no email is selected, do you have an option for Mailboxes at the top left? If so, tap on it and select your inbox or possibly a listing for 'All Inboxes' if you have more than one account set up on your iPhone. Does this show you your inbox with emails you are receiving? If not, do you see an option anywhere at the top left or right with a Cancel option or a back (left) arrow?
Should you still be encountering an issue, let us know more about the device you're using the Mail app with and what results the steps above had.
Thanks.