vi /etc/exim4/exim4.conf

#MAIN CONFIGURATION SETTINGS
    #need change
    primary_hostname = mail.dom.local
    #need change
    domainlist local_domains = /etc/exim4/domains
hostlist   relay_from_hosts = 127.0.0.1
auth_advertise_hosts = *
daemon_smtp_ports = 25 : 465
disable_ipv6

keep_environment = PATH HOME

tls_on_connect_ports = 465
tls_advertise_hosts = *
tls_certificate = /etc/ssl/certs/mail.pem
tls_privatekey = /etc/ssl/certs/mail.pem

    log_file_path = syslog : /var/log/exim4/exim_%slog
    syslog_timestamp = false
    syslog_duplication = false
    syslog_processname = exim_mail

log_selector = \
        +all_parents \
        +lost_incoming_connection \
        +received_sender \
        +received_recipients \
        +smtp_confirmation \
        +smtp_syntax_error \
        +smtp_protocol_error \
        -queue_run

acl_smtp_rcpt = acl_check_rcpt
    #need change
    qualify_domain = dom.local

allow_domain_literals = false
never_users = root
rfc1413_hosts = *
rfc1413_query_timeout = 0s
ignore_bounce_errors_after = 5m
timeout_frozen_after = 3d
freeze_tell = postmaster
message_size_limit = 10M
split_spool_directory = true
smtp_banner = "ESMTP"

#ACCESS LISTS
begin acl
  acl_check_rcpt:
    accept
      local_parts = postmaster
      domains = +local_domains
      #require verify         = sender

    accept
      hosts = : 127.0.0.1
    accept
      authenticated = *
    deny
      sender_domains = +local_domains
      message = need auth for local domain
    deny
      condition = ${if eq{$sender_helo_name}{}{yes}{no}}
      message = HELO/EHLO required by SMTP RFC

    accept
      domains        = +local_domains
        endpass
      verify         = recipient
      message        = unknown user
    deny
      message = relay not permitted

#ROUTERS CONFIGURATION
begin routers
    dnslookup:
        driver = dnslookup
        domains = ! +local_domains
        transport = remote_smtp
        ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
        no_more

    system_aliases:
        driver = redirect
        data = ${lookup{$local_part}lsearch{/etc/aliases}}

    localuser:
        driver = accept
        #domains = /etc/exim4/domains
        domains = +local_domains
        local_parts = ${extract{4}{:}{${lookup{$local_part@$domain}lsearch{/etc/exim4/dovecot.users}}}}
        #local_parts = /etc/exim4/exim.users
        transport = local_delivery
        transport_home_directory = /data/mail

#TRANSPORTS CONFIGURATION
begin transports
    remote_smtp:
        driver = smtp

    local_delivery:
        driver = appendfile
        directory = /data/mail/$domain_data/$local_part_data
        maildir_format
        maildir_use_size_file
        delivery_date_add
        envelope_to_add
        return_path_add
        user = Debian-exim
        group = Debian-exim
        mode = 0660

#RETRY CONFIGURATION
begin retry
*                      *           F,2h,15m; G,16h,1h,1.5; F,4d,6h

#REWRITE CONFIGURATION
begin rewrite

vi /etc/exim4/dovecot.users

admin@dom.local:VerySecurityPassword:114:119:admin
user@dom2.local:VerySecurityPassword2:114:119:user

cat /etc/exim4/domains

dom.local
dom2.local
dom3.local
dom4.local