I have a Zimbra OSS 5.0.8 edition running on a single server (Ubuntu). It is running with a non-internet addressable domain eg nowhere.com. When I set this up I created a domain alias to add my internet domain.
I have a personal domain eg "nowhere.com"
I have use a dynamic DNS provider to allow internet connectivity inbound as I have a dynamic IP address eg "domain.com"
I also use a mail forwarder service service say "bigfoot.com"
Inbound mail goes to email@example.com who relay it to firstname.lastname@example.org who then send it to my server and the user at email@example.com.
Additionally in the zimbra admin console I have enabled "allow sending email from any address". This is so that mail can be sent as if it had come from "firstname.lastname@example.org"
This setup has been working fine.
My issue is when I create a calendar entry and add external people. My mail server creates the calendar entry and sends out the invites. However the receiver sees the invites as coming from "email@example.com" and not "firstname.lastname@example.org". this then causes mail to be bounced as the domain "nowhere.com" is not reachable.
Hopefully i have explained this ok. Can anyone help.