I don't know if i found a bug but here's what i've found on my problem:
I can't send a mail to a mailbox whose domain if defined on my server but does not exist on it.
My ISP is Orange.fr. They were known as Wanadoo.fr years ago. I have mailboxes created with the @wanadoo.fr. If i want to fetch my mail from these boxes i have to define this domain in ISPConfig3 and set a fetchmail task.
By doing this i can get all my mail on my server. I can send emails to anybody but people that have email adresses ending by @wanadoo.fr. If i do that i have the "User unknown in virtual mailbox table". Sending mails to other users that end with @orange.fr works fine.
A few days ago i tried building a server "by hand". Mailing the same way was working (the "relayhost=" field in main.cf of postfix is used to send every unknown adresses on the server to an external relay). When i use ISPConfig3 it doesn't. That leaves two possibilities:
- I have not configured correctly ISPConfig3
- There is a bug in ISPConfig3
Does this ring any bells to anybody?