Can't download mail from the server icloud account

Question

My icloud mail account will not download messages. I'm unable to access my inbox.
The message displayed when I push to download is can not connect to server.

Answer 1

Does your ISP offer a separate account for additional email addresses or are additional email addresses what is called an "alias" account or address to the primary account?
A separate account for an additional email address with the same provider has its own user name.
An "alias" account or email address to a primary account shares the same user name and password as the primary account.
You can created separate accounts in Mail with the same provider which has the same incoming mail server and you can use the same password for both accounts as long as each account has its own user name which is usually the portion of the email address in front of the @ sign and with some providers it is the entire email address.
I have set up the 2 email accounts within Mail, but when
trying to edit and save the "Advanced" preferences for my
2nd email account, I get an error message saying something
to the effect: " [email protected] is already being
used by another account".
This error message indicates the additional email account you created in Mail shares the same user name and password as the primary/existing account which you cannot create as a separate account in Mail.
If so, there is a way to access an alias account or address to a primary account without creating it as a separate account.
If so, do not delete the additional account created yet.