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+# Description
+
+This extension adds support for password expiration.
+It is designed to have expiration on users passwords. An email is sent when the password is expiring in 30 days, then 14 days, then 7 days.
+It is strongly inspired by https://abridge2devnull.com/posts/2014/09/29/dovecot-user-password-expiration-notifications-updated-4122015/, and adapted to fit with Postfix Admin & Roundcube's password plugin
+
+Expiration unit is day
+
+Expiration value for domain is set through Postfix Admin GUI
+
+# Installation
+
+Password Expiration is merged with PostfixAdmin - so no additional database changes should be necessary.
+
+
+## Database Fields 
+
+ * mailbox.password_expiry - timestamp, when the mailbox password expires.
+ * domain.password_expiry - default duration for when a password will expire
+
+Changes in MySQL/MariaDB mailbox table (as defined in `$CONF['database_tables']` from config.inc.php):
+
+## Changes in Postfix Admin :
+
+To enable password expiration, add the following to your config.inc.php file:
+
+`$CONF['password_expiration'] = 'YES';`
+
+## RoundCube Password Plugin
+
+If you are using Roundcube's password plugin, you should also adapt the `$config['password_query']` value.
+
+I recommend to use:
+
+`$config['password_query'] = 'UPDATE mailbox SET password=%c, modified = now(), password_expiry = now() + interval 90 day';`
+
+of course, you may adapt to the expiration value to suit.
+
+
+## Changes in Dovecot (adapt if you use another LDA)
+
+Edit dovecot-mysql.conf file, and replace the user_query (and only this one) to be based on this query:
+
+```
+password_query = SELECT username as user, password, concat('/var/vmail/', maildir) as userdb_var, concat('maildir:/var/vmail/', maildir) as userdb_mail, 20001 as userdb_uid, 20001 as userdb_gid, m.domain FROM mailbox m, domain d where d.domain = m.domain and m.username = '%u' AND m.active = '1' AND (m.password_expiry > now() or d.password_expiry = 0)
+```
+
+
+Of course, you may require to adapt the uid, gid, maildir and table to your setup.
+
+
+## Changes in system
+
+You need to have a script running on a daily basis to check password expiration and send emails 30, 14 and 7 days before password expiration. An example is given below.
+
+Edit the script to adapt the variables to your setup.
+
+This script is using `postfixadmin.my.cnf` to read credentials, which might look a bit like : 
+
+```ini
+[client]
+user = me
+password = secret
+host = hostname
+```
+
+Edit this file to enter a DB user that is allowed to access (read-write) your database. This file should be protected from any user (chmod 400).
+
+### Expiration Script 
+
+```bash
+#!/bin/bash
+
+#Adapt to your setup
+
+POSTFIX_DB="postfixadmin"
+MYSQL_CREDENTIALS_FILE="postfixadmin.my.cnf"
+
+REPLY_ADDRESS=noreply@example.com
+
+# Change this list to change notification times and when ...
+for INTERVAL in 30 14 7
+do
+    LOWER=$(( $INTERVAL - 1 ))
+
+    QUERY="SELECT username,password_expiry FROM mailbox WHERE password_expiry > now() + interval $LOWER DAY AND password_expiry < NOW() + interval $INTERVAL DAY"
+
+    mysql --defaults-extra-file="$MYSQL_CREDENTIALS_FILE" "$POSTFIX_DB" -B -N -e "$QUERY" | while IFS=$'\t' read -a RESULT ; do
+        echo -e "Dear User, \n Your password will expire on ${RESULT[1]}" | mail -s "Password 30 days before expiration notication" -r $REPLY_ADDRESS  ${RESULT[0]} 
+    done
+done
+
+```