Email - Mailbox

About

A mailbox is a file where the emails message are stored.

A user application (known as MUA) can read and write a mailbox
The Mail Delivery Agent will write the email received by the SMTP server (MTA)

It can be real or virtual.

Management

Modification

Remotely (POP, IMAP)

You can modify a remote mailbox via the remote protocol POP and IMAP

FetchMail can also retrieve the email via POP and IMAP and stores them locally

Locally

You can modify local mail box With mail client utility

Example on how to to delete the mail 1 to 15 with mailx

mail
d 1-15
quit

Linux

Path

The default in post fix is /var/mail or /var/spool/mail. See postconf.5.html

sudo ls /var/mail

Two mailbox

root  user

Set the path with the MAIL environment variable

The MAIL environment variable set the path of the mailbox.

Example:

MAIL=/var/spool/mail/nico

Content

UNIX mailboxes: A mailbox file is just a collection of text mail separated by --multipart-boundary--

Example:

--multipart-boundary--

From [email protected]  Wed Jun 10 03:10:08 2020
Return-Path: <[email protected]>
Received: from example.com (localhost [127.0.0.1])
	by example.com (8.14.7/8.14.7) with ESMTP id 05A1A7A9005523
	for <[email protected]>; Wed, 10 Jun 2020 03:10:07 +0200
Received: (from root@localhost)
	by example.com (8.14.7/8.14.7/Submit) id 05A1A7dG005522
	for root; Wed, 10 Jun 2020 03:10:07 +0200
Date: Wed, 10 Jun 2020 03:10:07 +0200
Message-Id: <[email protected]>
From: Anacron <[email protected]>
To: [email protected]
Content-Type: text/plain; charset="UTF-8"
Subject: Anacron job 'cron.daily' on example.com

/etc/cron.daily/logrotate:

error: skipping "/var/log/php-fpm/error.log" because parent directory has insecure permissions (It's world writable or writable by group which is not "root") Set "su" directive in config file to tell logrotate which user/group should be used for rotation.
error: skipping "/var/log/php-fpm/www-error.log" because parent directory has insecure permissions (It's world writable or writable by group which is not "root") Set "su" directive in config file to tell logrotate which user/group should be used for rotation.