I have noticed that webmail.example.com does not work as expected with multisite Wordpress on subdomain as well as subdirectory. In both the case webmail.example.com is getting redirected to example.com. If I delete the website “ee site delete example.com” , then webmail.example.com loads roundcube again.
Apart from this wp-admin page isn’t redirecting to dashboard, in case of multisite subdirectory installation. I mean I am unable to login as admin.