Right, I've got rc-vacation
https://github.com/bhuisgen/rc-vacation installed and it's mostly working. I'm using ubuntu, postfix, mysql, dovecot and that.
Whenever I enable it, it creates an alias for user test@testdomain.com and points it to test@testdomain.com,test#testdomain.com@autoreply.my.domain
Then the sender of the original message gets a bounceback saying that they can't send mail to test#testdomain.com@autoreply.my.domain, because obviously that domain doesn't exist, although the original message gets through to the recipient.
Now that autoreply.my.domain, is it meant to literally be autoreply.my.domain or should it be localhost or something dynamic or do I need to modify the postfix conf to handle that somehow or what?