I have a site setup as follows: site: www.domain.com co-domain: domain.com The e-mail for this site is hosted on an exchange server at a different location. If I try sending e-mail from a different site on the ispconfig server (using roundcube webmail), it fails to sent. I believe it's failing because it's looking on the ispconfig server for the user being sent to and that user doesn't exist. If I remove the co-domain, the e-mail seems to deliver from the isp config server to the exchange server. But if I do that, people can't access the site without the host name anymore (http://domain.com). Is there a way to keep the co-domain (to allow both http://www.domain.com and http://domain.com) and allow email delivery to a different server? Thanks in advance.