View source for Dovecot

= Dovecot =

Using your local QNAP storage as a local E-Mail archive accessable via IMAP from local network or even via VPN from remote.

Authentication: local password of local pre-configured users

This instructions are based on QTS 5.0.1 on TS-453

== Prerequisites ==

=== App Center archive extension ===

Via Web-UI: Enable QNAPclub in App Center as additional App archive

URL: https://www.qnapclub.eu/en/repo.xml

=== Entware ===

Install via App Center: Entware-std (version 1.03 on time of writing)

== Installation ==

Login via SSH

Install via "opkg" required packages

<pre>
opkg update
opkg install dovecot dovecot-utils
</pre>

== Configuration ==

=== System Users  ===

Create for Dovecot required system users

<pre>
useradd -r -c "Dovecot IMAP server" -M -d /opt/libexec/dovecot -s /sbin/nologin dovecot 
useradd -r -c "Dovecot's unauthorized user" -M -d /opt/libexec/dovecot -s /sbin/nologin dovenull
</pre>

=== TLS Preparation ===

Create e.g. via XCA a local CA and issue server certificate for your QNAP system

Hint: configure additional "Subject Alternative Names" to match all possibilities like:
*Internal IP address
*Internal short hostname
*Internal automatically assigned hostname, e.g. MY-QNAP.fritz.box

Store the created public part TLS Certificate of the server in PEM format into directory

<pre>/opt/etc/ssl/certs/</pre>

Store the private key of the TLS Certificate (without passphrase to be reboot-safe) of the server in PEM format into directory

<pre>/opt/etc/ssl/private/</pre>

=== Create local Dovecot configuration file ===

Replace "MY-QNAP-TLS.crt" and "MY-QNAP-TLS.key" with names used above

<pre>
cat <<END >/opt/etc/dovecot/local.conf 
protocols = imap
 
ssl_cert = </opt/etc/ssl/certs/MY-QNAP-TLS.crt
ssl_key = </opt/etc/ssl/private/MY-QNAP-TLS.key
 
userdb {
  driver = passwd
}
 
passdb {
  driver = shadow
}
 
service imap-login {
	chroot =
}
END
</pre>


=== Disable unusued configuration files ===

<pre>
mv /opt/etc/dovecot/conf.d/10-ssl.conf /opt/etc/dovecot/conf.d/10-ssl.conf.unused
mv /opt/etc/dovecot/conf.d/10-auth.conf /opt/etc/dovecot/conf.d/10-auth.conf.unused
</pre>

=== Maildir setup per user ===

Replace content of IMAP_USER_LIST to your users which should be allowed to use the QNAP storage as IMAP server

<pre>
IMAP_USER_LIST="user1 user2 user3"

for u in $IMAP_USER_LIST; do
mkdir -p /share/homes/$u/Maildir/{cur,new,tmp}
chown -R $u /share/homes/$u/Maildir
done
</pre>


=== Start Dovecot ===

<pre>
/opt/etc/init.d/S90dovecot start
</pre>

== Troubleshooting ==

=== Logging ===

Unfortunately no log file is written (at least none were found so far)

=== Tracing ===

Stop dovecot

<pre>
/opt/etc/init.d/S90dovecot stop
</pre>

and run in foreground mode

<pre>
/opt/sbin/dovecot -F -c /opt/etc/dovecot/dovecot.conf
</pre>

in worst case, install "strace" via "opkg" and run in foreground using "strace"

<pre>
strace /opt/sbin/dovecot -F -c /opt/etc/dovecot/dovecot.conf
</pre>

== Backup ==

=== Configuration ===

Include following directory into backup: /opt/etc/

=== User Data ===

Include following directory pattern into backup: /share/homes/*/Maildir/


== Notes ==

The "Maildir" tree per user is portable and can be even accessed after copy to a Linux system using e.g. "mutt"

[[Category:Adding new services]]