Today’s snippet is from Run Your Own Mail Server. Here’s a tidbit about the link between Unix accounts and email addresses.
I expected to be further along, but Apache and X.509 had different ideas. Delay: yet another service they provide!
Your test system is set up the same way most twentieth-century mail systems were. Each email address is associated with a Unix account. Adding a Unix account automatically creates a matching email address. Email addresses without Unix accounts are processed by the aliases file as discussed in Chapter 1. If an address has neither an account nor an alias, the address is invalid.
This is undesirable for most modern systems, even if you’re truly running email for only yourself. If you want additional accounts for friends, family, or a small organization, it’s a disaster. Perhaps my half-Wookie-but-balding uncle needs an email account at the family domain, but I know for a fact that he answers every hair restoration spam and he doesn’t understand the difference between Netflix and his cell phone. His email should not be tied to a Unix account or, indeed, any system access whatsoever.
The book’s still open for sponsorships, if you’re interested.