Auto receive email and errors with address book

Two questions actually.
1. Some of the users are having trouble receiving emails automatically.
Their Outlook is set to automatically check for new email every X minutes,
but new email is not displayed until they click "New" to start a new message.
Even clicking Send/Receive does not help.
2. Some users were exclusively using Outlook Express to check email, but
now they are trying to use Outlook for both Internet email and Exchange
messaging. However, their address book in Outlook is not working right in
that a dot (.) is being inserted between the username and "@" in the email
address. The email bounces back as undeliverable.

Thanks in advance for any help!