I am quite experienced with Linux but a beginner with email configuration and with postfix.On my desktop I have installed Ubuntu Linux 10.04 with package postfix 2.8.5-2~build0.10.04.I have configured postfix to send email through my ISP and this works fine: I can open mutt and send an email to an external address (e.g. google) and the email is delivered correctly.The next thing I wanted to do was to define a mapping so that if I send a local email, it is delivered to my address which has the form:my-username@my-isp-provider.netIn order to do this, I followed the postfix documentation and configured postfix as follows:/etc/postfix/main.cf:    smtp_generic_maps = hash:/etc/postfix/generic/etc/postfix/generic:    @my-hostname       my-username@my-isp-provider.net    @localhost         my-username@my-isp-provider.netSo, if I have understood the documentation correctly, this should cause all messages sent to any local user user-x with the addresses user-x@my-hostname and user-x@localhost to be delivered to my-username@my-isp-provider.net.Instead, I observe the following unexpected behaviour:If I send email to my-username@localhost, the message is delivered to my Linux box and not to my ISP account my-username@my-isp-provider.net.Even more strangely, my ISP administrator has sent me an email, that they are receiving messages for destination root@my-isp-provider.net with subject 'Subject: Anacron job 'cron.daily' on my-hostname'. I suppose this is a local notification of my Linux box that is meant for root, but how does this get mapped to root@my-isp-provider.net?At the moment I have checked all my configuration files and I have not clue as to how I can explain this behaviour:Why are my messages to address my-username@localhost not mapped to my-username@my-isp-provider.net as specified in the configuration file?Where do these messages for root@my-isp-provider.net come from, if the only mapping I have specifies the complete address of the receiver (my-username@my-isp-provider.net) explicitly? So if a message for root@locahost gets mapped, it should be delivered to my-username@my-isp-provider.net and not to root@my-isp-provider.net.
Ubuntu email: Wrong (and unexpected) postfix mapping
ubuntu;postfix