A Linux system account: what it is, and which numbers it holds.
What this account is
Owns the group on mailboxes under /var/mail and the write access that implies, an arrangement fixed by Debian Policy. Mail transfer and user agents also use the account for their own purposes.
Source: base-passwd, doc/users-and-groups.sgml, edition 0.2
Sources
| Distribution | Source package | Package version | Commit | Read from source |
|---|---|---|---|---|
| Debian | base-passwd | 3.6.8 | a080557e1d59 | 2026-08-07 |
| Alpine Linux | alpine-baselayout | 3.7.2 | a9c597c5cee0 | 2026-08-07 |