main.cf
a message, including envelope information. Default is 10240000
message_size_limit = 130000000
mailbox_size_limit limits the max. size of local mailboxes. Default is 51200000
mailbox_size_limit = 0
some basic path definitions
command_directory = /usr/sbin
daemon_directory = /usr/lib/postfix/sbin
some basic mail system settings
myhostname = KopanoM.hs-xxx.intranet
mydomain is unset - The default is to use $myhostname minus the first component.
myorigin = KopanoM.hs-xxx.intranet
smtp_helo_name = KopanoM.hs-xxx.intranet
append_dot_mydomain = no
compatibility_level = 3
inet_interfaces = all
inet_protocols = ipv4
mydestination = $myhostname, localhost.$mydomain, localhost
mynetworks = 127.0.0.0/8
mynetworks_style = subnet
masquerade_domains = $mydomain
masquerade_exceptions = root
transport_maps = hash:/etc/postfix/transport
relay_domains = $mydestination
we need to name a smtp relay host to which we forward non-local
mails. smtp authentication is also possible.
relayhost = smtp.ionos.de
smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
smtp_sasl_password_maps = hash:/etc/postfix/smtp_auth
disable_vrfy_command = no
banner
smtputf8_enable = no
prevent STMP Smuggling CVE-2023-51764 / Bug 56957
local_header_rewrite_clients = static:all
virtual_alias_domains =
virtual_alias_maps = hash:/etc/postfix/virtual,
ldap:/etc/postfix/ldap.groups,
ldap:/etc/postfix/ldap.distlist,
ldap:/etc/postfix/ldap.virtual,
ldap:/etc/postfix/ldap.external_aliases,
ldap:/etc/postfix/ldap.sharedfolderremote,
ldap:/etc/postfix/ldap.sharedfolderlocal_aliases
virtual_mailbox_domains = ldap:/etc/postfix/ldap.virtualdomains
virtual_mailbox_maps = ldap:/etc/postfix/ldap.virtual_mailbox,
ldap:/etc/postfix/ldap.sharedfolderlocal
virtual_transport = lmtp:127.0.0.1:2003
canonical_maps = hash:/etc/postfix/canonical
relocated_maps = hash:/etc/postfix/relocated
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
postscreen settings
postscreen_dnsbl_action = enforce
postscreen_dnsbl_threshold = 3
postscreen_dnsbl_sites =
postscreen_helo_required = no
postscreen_greet_action = drop
postscreen_greet_ttl = 1d
postscreen_non_smtp_command_enable = no
postscreen_non_smtp_command_action = ignore
postscreen_bare_newline_enable = no
postscreen_bare_newline_action = ignore
postscreen_blacklist_action = ignore
postscreen_access_list = permit_mynetworks
cidr:/etc/postfix/postscreen_access.cidr
smtpd_sender_restrictions is not defined since all relevant checks have been moved to
smtpd_recipient_restrictions (see below) and every mail has to pass smtpd_recipient_restrictions too.
#smtpd_sender_restrictions =
smtpd_recipient_restrictions = permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination,
reject_unlisted_recipient
special recipient_restrictions which may be used by smtps/submission services
(can be configured via UCR: mail/postfix/submission/restrictions/recipient/…)
submission_recipient_restrictions =
#TLS settings
smtpd_use_tls = yes
smtpd_tls_auth_only = yes
smtpd_starttls_timeout = 300s
smtpd_timeout = 300s
smtpd_tls_mandatory_protocols = !SSLv2,!SSLv3
smtpd_tls_protocols =
smtpd_tls_exclude_ciphers = RC4, aNULL
smtpd_tls_cert_file = /etc/univention/letsencrypt/signed_chain.crt
smtpd_tls_key_file = /etc/univention/letsencrypt/domain.key
smtpd_tls_CAfile = /etc/univention/letsencrypt/signed_chain.crt
smtpd_tls_received_header = no
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
smtpd_sasl_local_domain =
smtpd_sasl_security_options = noanonymous
smtp client
smtp_tls_security_level = may
smtp_tls_mandatory_protocols = !SSLv2,!SSLv3
smtp_tls_protocols = !SSLv2,!SSLv3
smtp_tls_exclude_ciphers = RC4, aNULL
smtp_tls_policy_maps = hash:/etc/postfix/tls_policy
Support broken clients like Microsoft Outlook Express 4.x which expect AUTH=LOGIN instead of AUTH LOGIN
broken_sasl_auth_clients = yes
tls logging
smtp_tls_loglevel = 0
smtpd_tls_loglevel = 0
EDH config
smtpd_tls_dh1024_param_file = /etc/postfix/dh_2048.pem
smtpd_tls_dh512_param_file = /etc/postfix/dh_512.pem
use the Postfix SMTP server’s cipher preference order instead of the remote client’s cipher preference order.
tls_preempt_cipherlist = yes
The Postfix SMTP server security grade for ephemeral elliptic-curve Diffie-Hellman (EECDH) key exchange
smtpd_tls_eecdh_grade = strong
if virus scanning is desired, all mails can be redirected through amavis.
content_filter = smtp-amavis:[127.0.0.1]:10024
The following section is included from the file /etc/postfix/main.cf.local.
Please note, that custom options in this file may interfere with the
standard Postfix configuration of Univention Corporate Server!
#Absenderabhaengige Zuweisung von SMTP Servern
#d.h. jeder Zarafa Benutzer kann seinen eigenen SMTP haben
#sender_dependent_relayhost_maps = yes
smtp_sender_dependent_authentication = yes
smtp_sasl_auth_enable = yes
noplaintext weglassen, wenn Passwoerter Klartext uebertragen werden muessen,
d.h. wenn in der sasl_password die Passwoerter im Klattext verwaltet:
(nicht empfohlen, nur wenn’s anders nicht funktioniert)
smtp_sasl_security_options = noanonymous
smtp_connection_cache_on_demand = no
smtp_sasl_password_maps = hash:/etc/postfix/smtp_auth
sender_dependent_relayhost_maps = hash:/etc/postfix/sender_relay
sender_canonical_maps = hash:/etc/postfix/sender_canonical