After recently setting up a mail server I am now adding the users that I need. As part of the tutorial I followed I created root@localhost as an account and also a bunch of aliases (postmaster@localhost, webmaster@localhost etc).
What is the point of having al these localhost addresses? it seems that no one can ever mail them directly...
Also I am curious as to what targets I should include on my domain (like postmaster, root, webmaster etc) and what ramifications there might be for doing so?
Some system and reporting tools may try to drop messages to root@localhost or other accounts as part of a notification strategy. They're good to have around as users and software on the system can usually rely on those accounts being present to get important information to the right person.
As for role accounts, the RFCs that govern e-mail delivery prescribe the
postmasterandabusemailboxes for each domain. Some systems will probe for these accounts and it's good to have them in place to avoid problems (like ending up on the rfc-ignorant.org blacklist, for one).Other role mailboxes are at your discretion. Having common mailbox names such as
webmasterorsalesmay make it easier for people to contact an appropriate person without having to hunt an address down on your website. On the other hand, you may get slightly more spam on those common addresses than you would otherwise. It's really a matter of how you expect your users to attempt to contact you.