Migration error from Exchange 2007 to Exchange 2013

Hi,

I installed new Exchange server 2013 on a separate windows server 2012.

already finished migration database from old server exchange 2007 to new 2013.

Now, I have some issues as below:;

1. client can use OWA by server IP address only. cannot use by name.

2. outlook client cannot auto change setting to new server. new server name appear strange: "0c1d1c80-7eb5-45d9-9ac4-d8f3dbb18ea2@company.com"

3. after opening outlook, error noticed: "There is a problem with the proxy server's security certificate. The name on the security sertificate is invalid or deos not match the name of the target site mail.company.com. Outlook is unable to connect to the proxy server (error code 10)"

But test email send/receive is ok.

Can you please help or advice any solution.

Thanks.

Ha.