Hi. I have followed the Perfect Ubuntu setup to the letter, but I am still getting errors. I have an odd setup, which may be giving errors to do with DNS.. it is: idealcare.co.uk = 18.104.22.168 (Web server externally hosted) mail.idealcare.co.uk = 22.214.171.124 (Mail server hosted in Head Office) ..obviously I have MX set up properly. We are migrating from Exchange Server which previously worked but was unreliable. I have installed ISPConfig and made a new user (web1_user), and configured Outlook. But when sending mails I get this: Code: The following recipient(s) cannot be reached: [email protected][email protected][email protected][email protected] Any help is greatly appreciated. It's driving me mad. Thanks for reading. James.