It's assumed that you have already installed and configured Postfix according to this tutorial:
Installing Postfix with MySql backend and SASL for SMTP authentication

1. Install required packages

apt-get install dovecot-imapd dovecot-pop3d


2. Configure Dovecot (pico /etc/dovecot/dovecot.conf)

mail_location = maildir:/home/vmail/%d/%n
auth default {
passdb sql {
args = /etc/dovecot/dovecot-sql.conf
}
userdb sql {
args = /etc/dovecot/dovecot-sql.conf
}
}
disable_plaintext_auth = no
user = vmail


Add or edit the above properties and leave everything else with the default value or configure according to your needs

3. Configure the MySql connector (pico /etc/dovecot/dovecot-sql.conf)

driver = mysql
connect = host=127.0.0.1 dbname={database} user={username} password={password}
default_pass_scheme = CRYPT
password_query = SELECT email as user, password FROM users WHERE email = '%u'
user_query = SELECT CONCAT('/home/vmail/',SUBSTRING_INDEX(email,'@',-1),'/',SUBSTRING_INDEX(email,'@',1),'/') as home, '5000' as uid, '5000' as gid FROM users WHERE email = '%u'


{database} = MySql database name
{username} = MySql username
{password} = MySql password

4. Restart Dovecot daemon

/etc/init.d/dovecot restart


1. Install imapsync

apt-get install imapsync


2. Sync the mailboxes

imapsync --host1 {host1} --user1 {user1} --password1 {password1} --host2 {host2} --user2 {user2} --password2 {password2} --subscribe


{host1}: The source mail server's host or ip address
{user1}: User name on the source mail server
{password1}: Password on the source mail server
{host2}: The destination mail server's host or ip address
{user2}: User name on the destination mail server
{password2}: Password on the destination mail server

When moving between different server software you may need to add or remove prefixes. For example when moving from dovecot to courier you need to add this parameter to remove the INBOX. prefix from the folder names: --prefix1 INBOX.

It's assumed that you have already installed and configured Postfix according to this tutorial:
Installing Postfix with MySql backend and SASL for SMTP authentication

1. Install required packages

apt-get install dovecot-imapd dovecot-pop3d


2. Configure Dovecot (pico /etc/dovecot/dovecot.conf)

protocols = imap imaps pop3 pop3s
ssl_disable = no
mail_location = maildir:/home/vmail/%d/%n
auth default {
passdb sql {
args = /etc/dovecot/dovecot-sql.conf
}
userdb sql {
args = /etc/dovecot/dovecot-sql.conf
}
}
disable_plaintext_auth = no
user = vmail


Add or edit the above properties and leave everything else with the default value or configure according to your needs

3. Configure the MySql connector (pico /etc/dovecot/dovecot-sql.conf)

driver = mysql
connect = host=127.0.0.1 dbname={database} user={username} password={password}
default_pass_scheme = CRYPT
password_query = SELECT email as user, password FROM users WHERE email = '%u'
user_query = SELECT CONCAT('/home/vmail/',SUBSTRING_INDEX(email,'@',-1),'/',SUBSTRING_INDEX(email,'@',1),'/') as home, '5000' as uid, '5000' as gid FROM users WHERE email = '%u'


{database} = MySql database name
{username} = MySql username
{password} = MySql password

4. Restart Dovecot daemon

/etc/init.d/dovecot restart


It's assumed that you have already installed and configured Postfix according to this tutorial: Installing Postfix with MySql backend and SASL for SMTP authentication

1. Install required packages

apt-get install courier-authdaemon courier-authlib-mysql courier-pop courier-pop-ssl courier-imap courier-imap-ssl


2. Make Courier use MySql backend (pico /etc/courier/authdaemonrc)

authmodulelist="authmysql"


3. Configure the MySql connector (pico /etc/courier/authmysqlrc)

MYSQL_SERVER 127.0.0.1
MYSQL_USERNAME {username}
MYSQL_PASSWORD {password}
MYSQL_PORT 0
MYSQL_DATABASE {database}
MYSQL_USER_TABLE users
MYSQL_CRYPT_PWFIELD password
MYSQL_UID_FIELD 5000
MYSQL_GID_FIELD 5000
MYSQL_LOGIN_FIELD email
MYSQL_HOME_FIELD "/home/vmail"
MYSQL_MAILDIR_FIELD CONCAT(SUBSTRING_INDEX(email,'@',-1),'/',SUBSTRING_INDEX(email,'@',1),'/')
MYSQL_QUOTA_FIELD quota


{database} = MySql database name
MySql username
MySql password

4. Restart Courier daemons

/etc/init.d/courier-authdaemon restart
/etc/init.d/courier-imap restart
/etc/init.d/courier-imap-ssl restart
/etc/init.d/courier-pop restart
/etc/init.d/courier-pop-ssl restart


1. Install required packages

apt-get install courier-authdaemon courier-authlib-mysql courier-pop courier-pop-ssl courier-imap courier-imap-ssl


2. Make the auth daemon support MySql virtual users (pico /etc/courier/authdaemonrc)

authmodulelist="authmysql"


3. Configure courier to use MySql backend (pico /etc/courier/authmysqlrc)

MYSQL_SERVER {mysql_host}
MYSQL_USERNAME {mysql_username}
MYSQL_PASSWORD {mysql_password}
MYSQL_PORT 0
MYSQL_DATABASE {mysql_database}
MYSQL_USER_TABLE users
MYSQL_CRYPT_PWFIELD password
MYSQL_UID_FIELD 5000
MYSQL_GID_FIELD 5000
MYSQL_LOGIN_FIELD email
MYSQL_HOME_FIELD "/home/vmail"
MYSQL_MAILDIR_FIELD CONCAT(SUBSTRING_INDEX(email,'@',-1),'/',SUBSTRING_INDEX(email,'@',1),'/')
MYSQL_QUOTA_FIELD quota


4. Restart affected daemons

/etc/init.d/courier-authdaemon restart
/etc/init.d/courier-imap restart
/etc/init.d/courier-imap-ssl restart
/etc/init.d/courier-pop restart
/etc/init.d/courier-pop-ssl restart


You can now connect to your server on port 110 for pop3, 995 for pop3s, 143 for imap and 993 for imaps.