Error sending to distribution list from external address.
I am new to Zimbra and got my first server up and running :)
I have set up a distribution list with both internal and external email-addresses and when a external member of the list sends a email to the server it tries to send it back with the original "From" and "Reply to" field.
The external sender then receives a error message from its own mailserver stating you have to log on before sending emails.
It seems like the function to change "From" and "Reply to" to the same as the distibution list address does not work.
I have set this up in the graphical view (with swedish language).
I´m running the latest version (8.0.6) on Ubuntu 12.04
Does anybody know how to fix this?