Gnarwl

apt-get install gnarwl
adduser --system --home /var/lib/gnarwl --no-create-home --gid 8 gnarwl
chown gnarwl: -R /var/lib/gnarwl /etc/gnarwl.cfg

Fichier /etc/postfix/master.cf :

# Gnarwl
gnarwl    unix  -       n       n       -       1       pipe flags=F
  user=gnarwl argv=/usr/bin/gnarwl -c /etc/gnarwl.cfg -a ${nexthop}

Fichier /etc/gnarwl.cfg :

server ldap.example.com
login uid=gnarwl,ou=sysaccounts,o=example
password mdpldap
base o=example
queryfilter (&(|(mail=$recepient)(mailAlternateAddress=$recepient))(vacationActive=TRUE))
mta /usr/sbin/sendmail -f $recepient -t $sender
charset UTF-8
loglevel 2

Il suffira ensuite d'envoyer le mail automatiquement sur le transport gnarwl:. Différente solutions existent pour cela :

Le principe : Utiliser un mapping LDAP pour ajouter automatiquement une adresse mail destinatrice en BCC via la directive recipient_bcc_maps. L'adresse mail ajouté sera dans un domaine spécial dont les mails seront destinés au transport gnarwl:

Fichier /etc/postfix/main.cf :

transport_maps = proxy:ldap:gnarwl_transport

ldap_mailbox_vacation_bcc_server_host = ldap0.example.com,ldap1.example.com
ldap_mailbox_vacation_bcc_server_port = 389
ldap_mailbox_vacation_bcc_search_base = o=example
ldap_mailbox_vacation_bcc_timeout = 30
ldap_mailbox_vacation_bcc_query_filter = (&(|(mail=%s)(mailAlternateAddress=%s))(vacationActive=TRUE))
ldap_mailbox_vacation_bcc_result_attribute = uid
ldap_mailbox_vacation_bcc_result_format = %s@autoreponse.example.com
ldap_mailbox_vacation_bcc_expansion_limit = 1
ldap_mailbox_vacation_bcc_scope = sub
ldap_mailbox_vacation_bcc_bind = yes
ldap_mailbox_vacation_bcc_version = 3
ldap_mailbox_vacation_bcc_bind_dn = uid=postfix,ou=sysaccounts,o=example
ldap_mailbox_vacation_bcc_bind_pw = mdpldap

recipient_bcc_maps = ldap:ldap_mailbox_vacation_bcc

gnarwl_transport_server_host = ldap0.example.com,ldap1.example.com
gnarwl_transport_server_port = 389
gnarwl_transport_search_base = o=example
gnarwl_transport_domain = autoreponse.example.com
gnarwl_transport_query_filter = (&(vacationActive=TRUE)(uid=%u))
gnarwl_transport_result_attribute = mail
gnarwl_transport_result_format = gnarwl:%s
gnarwl_transport_expansion_limit = 1
gnarwl_transport_scope = sub
gnarwl_transport_bind = yes
gnarwl_transport_version = 3
gnarwl_transport_cache = no
gnarwl_transport_bind_dn = uid=postfix,ou=sysaccounts,o=example
gnarwl_transport_bind_pw = mdpldap