These are the contents of '/etc/aliases' file on my Debian (Wheezy) server, as it is:
# /etc/aliases mailer-daemon: postmaster postmaster: root nobody: root hostmaster: root usenet: root news: root webmaster: root www: root ftp: root abuse: root noc: root security: root root: t
1. I noticed that, by default, my server sends email from what looks like
email@example.com. So, which one of the rules above governs this?
2. So, the rules in '/etc/aliases' are used to assign users to specific departments? That is, for example, all emails to be sent/received for 'abuse' will be delivered from/to firstname.lastname@example.org (which'd be the default email for root, unless there's an alias). Correct?
3. Can someone please explain what each of these really meant for -- mailer-daemon, postmaster, nobody, hostmaster, usenet, news, webmaster, www, ftp, abuse, noc, security, root?
I mean, a description like "
mailer-daemon for sending email delivery errors, but not really meant for receiving emails.
security for where people should contact your about security issues", or something like that.