ALIASES(5)

💖 ALIASES(5) 💖

okay bestie, gather round 🫶 this is the aliases file format manual — ALIASES(5), straight out of the File Formats Manual. yes it's a manpage, no it's not boring, i promise 💅

✨ NAME ✨

aliases — the aliases file for smtpd 🎀

🌸 DESCRIPTION 🌸

So this page explains the format of the aliases file, the one smtpd(8) uses. An alias, in its simplest form, is literally just assigning an arbitrary name to an email address or a whole group of email addresses. it's giving convenience ✨ — a super handy way to send mail. like, an alias could refer to all the users of a group, and mail sent to that alias would go to every member of the group. and that's just the simple version, because you can define way more complex aliases: an alias can refer to other aliases, be used to send mail to a file instead of another person, or even execute various commands. main character alias energy, fr fr 👑

Inside the file, # is a comment delimiter — anything placed after it gets discarded, no cap 🙈

The file is made up of key/value mappings of the form:

-filled -offset indent key: value1, value2, value3, ...

key is always folded to lowercase before alias lookups happen, so there can be no ambiguity, periodt. the key then expands to the corresponding values, and those values consist of one or more of the following:

• user — a user on the host machine 🧚 the user must have a valid entry in the passwd(5) database file, that part is not optional.
• /path/to/file — append messages to the file, specified by its absolute pathname 📁
• | command — pipe the message to command on its standard input. the command is run under the privileges of the daemon's unprivileged account 🔐
• : include: /path/to/file — include any definitions in the file as alias entries. the format of that file is identical to this one 🪞
• user-part@domain-part — an email address in RFC 5322 format 📧 if an address extension is appended to the user-part, it is first compared for an exact match. it is then stripped, so that an address such as user+ext@example.com will only use the part that precedes + as a key 💅
• error: code message — a status code and message to return. the code must be 3 digits, starting 4XX (TempFail) or 5XX (PermFail). the message must be present and can be freely chosen 🚨

heads up bestie: that error: code really does have to be 3 digits, and it really does have to start with 4XX (TempFail) or 5XX (PermFail). and the message? mandatory. no message, no vibes 😭

📂 FILES 📂

• /etc/opensmtpd/aliases — the default aliases file 🍓

👀 SEE ALSO 👀

smtpd.conf(5), makemap(8), newaliases(8), smtpd(8)

📜 HISTORY 📜

The aliases file format appeared in Bx 4.0 ⭐

that's a wrap, bestie 💜 this page is dated $Mdocdate: February 13 2021 $, and the footer stamps it as ALIASES(5) from the File Formats Manual — so go forth, write your aliases, and stay iconic 👑✨🎀