Originally Posted by till
An thats the reason why ispconfig uses webmail only trough the vhost by default
Apache is preventing the access to webmail for security reasons if your website does not use mod_php. If you use suphp, or suexec you will get blocked.
So to ensure I am grasping it, it won't work with suphp or suexec, but will with mod_php?
The other way I was thinking about trying it was with a new website "webmail.site1.com" though I think that wold require an additional DNS entry with the external DNS provider.