# this tutorial provided without any guarantee!
# only tested in ubuntu 16.04 64bit

--- 1st step ---
open /usr/local/vesta/bin/v-add-email
navigate to 'Action' and change to this

# Generating hashed password
# salt=$(generate_password "$PW_MATRIX" "8")
# md5="{md5}$($BIN/v-generate-password-hash md5 $salt <<<$password)"
crammd5="$($BIN/v-generate-password-cram-md5 $password)"

# Adding account info into password file
if [[ "$MAIL_SYSTEM" =~ exim ]]; then
    if [ "$quota" = 'unlimited' ]; then
        quota='0'
    fi
    str="$account:$crammd5:$user:mail::$HOMEDIR/$user:$quota"
    echo $str >> $HOMEDIR/$user/conf/mail/$domain/passwd
fi

--- 2nd step ---

create new file /usr/local/vesta/bin/v-generate-password-cram-md5
(important! make sure use same permission and group as others file)

edit v-generate-password-cram-md5
-----------------------------------------------------------------
#!/usr/local/vesta/php/bin/php
<?php
//# info: generate cram-md5
//# options: PASSWORD
//
//# The function generates password hash

// Checking arguments
if (empty($argv[1])) {
    echo "Error: not enought arguments\n";
    echo "Usage: " . $argv[0] ." PLAIN_PASSWORD \n";
    exit(1);
}

$password = $argv[1];

$hash = rtrim(shell_exec(escapeshellcmd("/usr/bin/doveadm pw -s CRAM-MD5 -p $password")));

// Printing result
echo $hash . "\n";
-----------------------------------------------------------------


--- 3th step ---

open /etc/dovecot/conf.d/10-auth.conf
edit to this
----
disable_plaintext_auth = yes
auth_verbose = yes
auth_mechanisms = cram-md5
----

--- 4th step ---
open /etc/dovecot/conf.d/auth-passwdfile.conf.ext
edit to this
----
passdb {
  driver = passwd-file
  args = scheme=cram-md5 username_format=%n /etc/exim4/domains/%d/passwd
}
----

--- 5th step ---
open /etc/dovecot/conf.d/10-master.conf
edit to this
----
service imap-login {
  inet_listener imap {
  address = 127.0.0.1
  }
  inet_listener imaps {
  }
}

service pop3-login {
  inet_listener pop3 {
  address = 127.0.0.1
  }
  inet_listener pop3s {
  }
}
----

--- 6th step ---
open /etc/exim4/exim4.conf.template
find this section >
######################################################################
#                   AUTHENTICATION CONFIGURATION                     #
######################################################################
--

change the content to this

######################################################################
#                   AUTHENTICATION CONFIGURATION                     #
######################################################################
begin authenticators

cram_md5:
  driver = cram_md5
  public_name = CRAM-MD5
  client_name = ${extract{1}{:}{${lookup{$host}nwildlsearch{CONFDIR/passwd.client}{$value}fail}}}
  client_secret = ${extract{2}{:}{${lookup{$host}nwildlsearch{CONFDIR/passwd.client}{$value}fail}}}

# this returns the matching line from passwd.client and doubles all ^
PASSWDLINE=${sg{\
                ${lookup{$host}nwildlsearch{CONFDIR/passwd.client}{$value}fail}\
	        }\
	        {\\N[\\^]\\N}\
	        {^^}\
	    }

#dovecot_plain:
#  driver = dovecot
#  public_name = PLAIN
#  server_socket = /var/run/dovecot/auth-client
#  server_set_id = $auth1

#dovecot_login:
#  driver = dovecot
#  public_name = LOGIN
#  server_socket = /var/run/dovecot/auth-client
#  server_set_id = $auth1

-----------------------------------------

--- 7th step ---
rm /usr/local/vesta/ssl/certificate.key
rm /usr/local/vesta/ssl/certificate.crt

create new file /usr/local/vesta/bin/v-update-cert
(important! make sure use same permission and group as others file)

edit v-update-cert
-----------------------------------------------------------------
#!/bin/bash
# info: update web templates
# options: [RESTART]
#
# The function to copy cert
#----------------------------------------------------------#
#                       Action                             #
#----------------------------------------------------------#

cp -u /home/admin/conf/web/ssl.<youdomain>.<tld>.key /usr/local/vesta/ssl/certificate.key
cp -u /home/admin/conf/web/ssl.<youdomain>.<tld>.pem /usr/local/vesta/ssl/certificate.crt
chmod 660 /usr/local/vesta/ssl/certificate.key
chmod 660 /usr/local/vesta/ssl/certificate.crt
chown -R mail: /usr/local/vesta/ssl/certificate.key
chown -R mail: /usr/local/vesta/ssl/certificate.crt

exit
-----------------------------------------------------------------
[Note]
add this to cron job to ensure its always get latest cert


--- 7th step ---
in terminal

service exim4 restart
service apache2 restart
service dovecot restart
service vesta restart