Hema16 Said:
"Mail app is a big problem: All emails does not show all emails for all accounts. I have to literally go into each account and go into all mail and important mail for each ac to see emails. mor sometimes if I search for the name it shows. Basically I would not even know if people have sent me email unless they call to check it.[...]"
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Are you Connected to the Internet?
You would need to be connected to the internet to make this work. So, connect to it, and see if it sends.
Expired App Password:
Do you use an App Password? Tf so, try a new App Password. It may need to resync it the App password has expired (something often seen after updating your device or other installations).
See how AOL Uses it:
As an example, here is how AOL uses an app password. You may need to use an app password. Go Here: Create and Manage Third-Party App Passwords - AOL Help