# Global Postfix configuration file. This file lists only a subset # of all parameters. For the syntax, and for a complete parameter # list, see the postconf(5) manual page (command: "man 5 postconf"). # # For common configuration examples, see BASIC_CONFIGURATION_README # and STANDARD_CONFIGURATION_README. To find these documents, use # the command "postconf html_directory readme_directory", or go to # http://www.postfix.org/BASIC_CONFIGURATION_README.html etc. # # For best results, change no more than 2-3 parameters at a time, # and test if Postfix still works after every change. # COMPATIBILITY # # The compatibility_level determines what default settings Postfix # will use for main.cf and master.cf settings. These defaults will # change over time. # # To avoid breaking things, Postfix will use backwards-compatible # default settings and log where it uses those old backwards-compatible # default settings, until the system administrator has determined # if any backwards-compatible default settings need to be made # permanent in main.cf or master.cf. # # When this review is complete, update the compatibility_level setting # below as recommended in the RELEASE_NOTES file. # # The level below is what should be used with new (not upgrade) installs. # compatibility_level = 2 # SOFT BOUNCE # # The soft_bounce parameter provides a limited safety net for # testing. When soft_bounce is enabled, mail will remain queued that # would otherwise bounce. This parameter disables locally-generated # bounces, and prevents the SMTP server from rejecting mail permanently # (by changing 5xx replies into 4xx replies). However, soft_bounce # is no cure for address rewriting mistakes or mail routing mistakes. # #soft_bounce = no # LOCAL PATHNAME INFORMATION # # The queue_directory specifies the location of the Postfix queue. # This is also the root directory of Postfix daemons that run chrooted. # See the files in examples/chroot-setup for setting up Postfix chroot # environments on different UNIX systems. # queue_directory = /var/spool/postfix # The command_directory parameter specifies the location of all # postXXX commands. # command_directory = /usr/local/sbin # The daemon_directory parameter specifies the location of all Postfix # daemon programs (i.e. programs listed in the master.cf file). This # directory must be owned by root. # daemon_directory = /usr/local/libexec/postfix # The data_directory parameter specifies the location of Postfix-writable # data files (caches, random numbers). This directory must be owned # by the mail_owner account (see below). # data_directory = /var/db/postfix # QUEUE AND PROCESS OWNERSHIP # # The mail_owner parameter specifies the owner of the Postfix queue # and of most Postfix daemon processes. Specify the name of a user # account THAT DOES NOT SHARE ITS USER OR GROUP ID WITH OTHER ACCOUNTS # AND THAT OWNS NO OTHER FILES OR PROCESSES ON THE SYSTEM. In # particular, don't specify nobody or daemon. PLEASE USE A DEDICATED # USER. # mail_owner = postfix # The default_privs parameter specifies the default rights used by # the local delivery agent for delivery to external file or command. # These rights are used in the absence of a recipient user context. # DO NOT SPECIFY A PRIVILEGED USER OR THE POSTFIX OWNER. # #default_privs = nobody # INTERNET HOST AND DOMAIN NAMES # # The myhostname parameter specifies the internet hostname of this # mail system. The default is to use the fully-qualified domain name # from gethostname(). $myhostname is used as a default value for many # other configuration parameters. # #myhostname = host.domain.tld #myhostname = virtual.domain.tld myhostname = mail.ahlawat.com # The mydomain parameter specifies the local internet domain name. # The default is to use $myhostname minus the first component. # $mydomain is used as a default value for many other configuration # parameters. # #mydomain = domain.tld mydomain = ahlawat.com # SENDING MAIL # # The myorigin parameter specifies the domain that locally-posted # mail appears to come from. The default is to append $myhostname, # which is fine for small sites. If you run a domain with multiple # machines, you should (1) change this to $mydomain and (2) set up # a domain-wide alias database that aliases each user to # user@that.users.mailhost. # # For the sake of consistency between sender and recipient addresses, # myorigin also specifies the default domain name that is appended # to recipient addresses that have no @domain part. # myorigin = $myhostname #myorigin = $mydomain # RECEIVING MAIL # The inet_interfaces parameter specifies the network interface # addresses that this mail system receives mail on. By default, # the software claims all active interfaces on the machine. The # parameter also controls delivery of mail to user@[ip.address]. # # See also the proxy_interfaces parameter, for network addresses that # are forwarded to us via a proxy or network address translator. # # Note: you need to stop/start Postfix when this parameter changes. # #inet_interfaces = all #inet_interfaces = $myhostname #inet_interfaces = $myhostname, localhost # The proxy_interfaces parameter specifies the network interface # addresses that this mail system receives mail on by way of a # proxy or network address translation unit. This setting extends # the address list specified with the inet_interfaces parameter. # # You must specify your proxy/NAT addresses when your system is a # backup MX host for other domains, otherwise mail delivery loops # will happen when the primary MX host is down. # #proxy_interfaces = #proxy_interfaces = 1.2.3.4 # The mydestination parameter specifies the list of domains that this # machine considers itself the final destination for. # # These domains are routed to the delivery agent specified with the # local_transport parameter setting. By default, that is the UNIX # compatible delivery agent that lookups all recipients in /etc/passwd # and /etc/aliases or their equivalent. # # The default is $myhostname + localhost.$mydomain + localhost. On # a mail domain gateway, you should also include $mydomain. # # Do not specify the names of virtual domains - those domains are # specified elsewhere (see VIRTUAL_README). # # Do not specify the names of domains that this machine is backup MX # host for. Specify those names via the relay_domains settings for # the SMTP server, or use permit_mx_backup if you are lazy (see # STANDARD_CONFIGURATION_README). # # The local machine is always the final destination for mail addressed # to user@[the.net.work.address] of an interface that the mail system # receives mail on (see the inet_interfaces parameter). # # Specify a list of host or domain names, /file/name or type:table # patterns, separated by commas and/or whitespace. A /file/name # pattern is replaced by its contents; a type:table is matched when # a name matches a lookup key (the right-hand side is ignored). # Continue long lines by starting the next line with whitespace. # # See also below, section "REJECTING MAIL FOR UNKNOWN LOCAL USERS". # mydestination = $myhostname, localhost.$mydomain, localhost #mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain #mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain, # mail.$mydomain, www.$mydomain, ftp.$mydomain # REJECTING MAIL FOR UNKNOWN LOCAL USERS # # The local_recipient_maps parameter specifies optional lookup tables # with all names or addresses of users that are local with respect # to $mydestination, $inet_interfaces or $proxy_interfaces. # # If this parameter is defined, then the SMTP server will reject # mail for unknown local users. This parameter is defined by default. # # To turn off local recipient checking in the SMTP server, specify # local_recipient_maps = (i.e. empty). # # The default setting assumes that you use the default Postfix local # delivery agent for local delivery. You need to update the # local_recipient_maps setting if: # # - You define $mydestination domain recipients in files other than # /etc/passwd, /etc/aliases, or the $virtual_alias_maps files. # For example, you define $mydestination domain recipients in # the $virtual_mailbox_maps files. # # - You redefine the local delivery agent in master.cf. # # - You redefine the "local_transport" setting in main.cf. # # - You use the "luser_relay", "mailbox_transport", or "fallback_transport" # feature of the Postfix local delivery agent (see local(8)). # # Details are described in the LOCAL_RECIPIENT_README file. # # Beware: if the Postfix SMTP server runs chrooted, you probably have # to access the passwd file via the proxymap service, in order to # overcome chroot restrictions. The alternative, having a copy of # the system passwd file in the chroot jail is just not practical. # # The right-hand side of the lookup tables is conveniently ignored. # In the left-hand side, specify a bare username, an @domain.tld # wild-card, or specify a user@domain.tld address. # #local_recipient_maps = unix:passwd.byname $alias_maps #local_recipient_maps = proxy:unix:passwd.byname $alias_maps #local_recipient_maps = # The unknown_local_recipient_reject_code specifies the SMTP server # response code when a recipient domain matches $mydestination or # ${proxy,inet}_interfaces, while $local_recipient_maps is non-empty # and the recipient address or address local-part is not found. # # The default setting is 550 (reject mail) but it is safer to start # with 450 (try again later) until you are certain that your # local_recipient_maps settings are OK. # unknown_local_recipient_reject_code = 550 # TRUST AND RELAY CONTROL # The mynetworks parameter specifies the list of "trusted" SMTP # clients that have more privileges than "strangers". # # In particular, "trusted" SMTP clients are allowed to relay mail # through Postfix. See the smtpd_recipient_restrictions parameter # in postconf(5). # # You can specify the list of "trusted" network addresses by hand # or you can let Postfix do it for you (which is the default). # # By default (mynetworks_style = subnet), Postfix "trusts" SMTP # clients in the same IP subnetworks as the local machine. # On Linux, this works correctly only with interfaces specified # with the "ifconfig" command. # # Specify "mynetworks_style = class" when Postfix should "trust" SMTP # clients in the same IP class A/B/C networks as the local machine. # Don't do this with a dialup site - it would cause Postfix to "trust" # your entire provider's network. Instead, specify an explicit # mynetworks list by hand, as described below. # # Specify "mynetworks_style = host" when Postfix should "trust" # only the local machine. # #mynetworks_style = class #mynetworks_style = subnet #mynetworks_style = host # Alternatively, you can specify the mynetworks list by hand, in # which case Postfix ignores the mynetworks_style setting. # # Specify an explicit list of network/netmask patterns, where the # mask specifies the number of bits in the network part of a host # address. # # You can also specify the absolute pathname of a pattern file instead # of listing the patterns here. Specify type:table for table-based lookups # (the value on the table right-hand side is not used). # #mynetworks = 168.100.189.0/28, 127.0.0.0/8 #mynetworks = $config_directory/mynetworks #mynetworks = hash:$config_directory/network_table #mynetworks = 127.0.0.1/32 192.168.0.0/16 [::1]/128 [fe80::]/10 [2603:3024:3f6::]/56 mynetworks = 127.0.0.1/32 192.168.0.0/24 [::1]/128 [fe80::]/10 [2603:3024:3f6:e1::]/64 smtp_bind_address = 192.168.0.100 smtp_bind_address6 = 2603:3024:3f6:e1::100 # The relay_domains parameter restricts what destinations this system will # relay mail to. See the smtpd_recipient_restrictions description in # postconf(5) for detailed information. # # By default, Postfix relays mail # - from "trusted" clients (IP address matches $mynetworks) to any destination, # - from "untrusted" clients to destinations that match $relay_domains or # subdomains thereof, except addresses with sender-specified routing. # The default relay_domains value is $mydestination. # # In addition to the above, the Postfix SMTP server by default accepts mail # that Postfix is final destination for: # - destinations that match $inet_interfaces or $proxy_interfaces, # - destinations that match $mydestination # - destinations that match $virtual_alias_domains, # - destinations that match $virtual_mailbox_domains. # These destinations do not need to be listed in $relay_domains. # # Specify a list of hosts or domains, /file/name patterns or type:name # lookup tables, separated by commas and/or whitespace. Continue # long lines by starting the next line with whitespace. A file name # is replaced by its contents; a type:name table is matched when a # (parent) domain appears as lookup key. # # NOTE: Postfix will not automatically forward mail for domains that # list this system as their primary or backup MX host. See the # permit_mx_backup restriction description in postconf(5). # #relay_domains = $mydestination # INTERNET OR INTRANET # The relayhost parameter specifies the default host to send mail to # when no entry is matched in the optional transport(5) table. When # no relayhost is given, mail is routed directly to the destination. # # On an intranet, specify the organizational domain name. If your # internal DNS uses no MX records, specify the name of the intranet # gateway host instead. # # In the case of SMTP, specify a domain, host, host:port, [host]:port, # [address] or [address]:port; the form [host] turns off MX lookups. # # If you're connected via UUCP, see also the default_transport parameter. # #relayhost = $mydomain #relayhost = [gateway.my.domain] #relayhost = [mailserver.isp.tld] #relayhost = uucphost #relayhost = [an.ip.add.ress] # REJECTING UNKNOWN RELAY USERS # # The relay_recipient_maps parameter specifies optional lookup tables # with all addresses in the domains that match $relay_domains. # # If this parameter is defined, then the SMTP server will reject # mail for unknown relay users. This feature is off by default. # # The right-hand side of the lookup tables is conveniently ignored. # In the left-hand side, specify an @domain.tld wild-card, or specify # a user@domain.tld address. # #relay_recipient_maps = hash:$config_directory/relay_recipients # INPUT RATE CONTROL # # The in_flow_delay configuration parameter implements mail input # flow control. This feature is turned on by default, although it # still needs further development (it's disabled on SCO UNIX due # to an SCO bug). # # A Postfix process will pause for $in_flow_delay seconds before # accepting a new message, when the message arrival rate exceeds the # message delivery rate. With the default 100 SMTP server process # limit, this limits the mail inflow to 100 messages a second more # than the number of messages delivered per second. # # Specify 0 to disable the feature. Valid delays are 0..10. # #in_flow_delay = 1s # ADDRESS REWRITING # # The ADDRESS_REWRITING_README document gives information about # address masquerading or other forms of address rewriting including # username->Firstname.Lastname mapping. # ADDRESS REDIRECTION (VIRTUAL DOMAIN) # # The VIRTUAL_README document gives information about the many forms # of domain hosting that Postfix supports. # "USER HAS MOVED" BOUNCE MESSAGES # # See the discussion in the ADDRESS_REWRITING_README document. # TRANSPORT MAP # # See the discussion in the ADDRESS_REWRITING_README document. # ALIAS DATABASE # # The alias_maps parameter specifies the list of alias databases used # by the local delivery agent. The default list is system dependent. # # On systems with NIS, the default is to search the local alias # database, then the NIS alias database. See aliases(5) for syntax # details. # # If you change the alias database, run "postalias /etc/aliases" (or # wherever your system stores the mail alias file), or simply run # "newaliases" to build the necessary DBM or DB file. # # It will take a minute or so before changes become visible. Use # "postfix reload" to eliminate the delay. # #alias_maps = dbm:/etc/aliases #alias_maps = hash:/etc/aliases #alias_maps = hash:/etc/aliases, nis:mail.aliases #alias_maps = netinfo:/aliases # The alias_database parameter specifies the alias database(s) that # are built with "newaliases" or "sendmail -bi". This is a separate # configuration parameter, because alias_maps (see above) may specify # tables that are not necessarily all under control by Postfix. # #alias_database = dbm:/etc/aliases #alias_database = hash:/etc/aliases #alias_database = hash:/etc/aliases, hash:/opt/majordomo/aliases # ADDRESS EXTENSIONS (e.g., user+foo) # # The recipient_delimiter parameter specifies the separator between # user names and address extensions (user+foo). See canonical(5), # local(8), relocated(5) and virtual(5) for the effects this has on # aliases, canonical, virtual, relocated and .forward file lookups. # Basically, the software tries user+foo and .forward+foo before # trying user and .forward. # recipient_delimiter = + # DELIVERY TO MAILBOX # # The home_mailbox parameter specifies the optional pathname of a # mailbox file relative to a user's home directory. The default # mailbox file is /var/spool/mail/user or /var/mail/user. Specify # "Maildir/" for qmail-style delivery (the / is required). # #home_mailbox = Mailbox #home_mailbox = Maildir/ # The mail_spool_directory parameter specifies the directory where # UNIX-style mailboxes are kept. The default setting depends on the # system type. # #mail_spool_directory = /var/mail #mail_spool_directory = /var/spool/mail mail_spool_directory = /data/local # The mailbox_command parameter specifies the optional external # command to use instead of mailbox delivery. The command is run as # the recipient with proper HOME, SHELL and LOGNAME environment settings. # Exception: delivery for root is done as $default_user. # # Other environment variables of interest: USER (recipient username), # EXTENSION (address extension), DOMAIN (domain part of address), # and LOCAL (the address localpart). # # Unlike other Postfix configuration parameters, the mailbox_command # parameter is not subjected to $parameter substitutions. This is to # make it easier to specify shell syntax (see example below). # # Avoid shell meta characters because they will force Postfix to run # an expensive shell process. Procmail alone is expensive enough. # # IF YOU USE THIS TO DELIVER MAIL SYSTEM-WIDE, YOU MUST SET UP AN # ALIAS THAT FORWARDS MAIL FOR ROOT TO A REAL USER. # #mailbox_command = /some/where/procmail #mailbox_command = /some/where/procmail -a "$EXTENSION" # The mailbox_transport specifies the optional transport in master.cf # to use after processing aliases and .forward files. This parameter # has precedence over the mailbox_command, fallback_transport and # luser_relay parameters. # # Specify a string of the form transport:nexthop, where transport is # the name of a mail delivery transport defined in master.cf. The # :nexthop part is optional. For more details see the sample transport # configuration file. # # NOTE: if you use this feature for accounts not in the UNIX password # file, then you must update the "local_recipient_maps" setting in # the main.cf file, otherwise the SMTP server will reject mail for # non-UNIX accounts with "User unknown in local recipient table". # # Cyrus IMAP over LMTP. Specify ``lmtpunix cmd="lmtpd" # listen="/var/imap/socket/lmtp" prefork=0'' in cyrus.conf. #mailbox_transport = lmtp:unix:/var/imap/socket/lmtp # # Cyrus IMAP via command line. Uncomment the "cyrus...pipe" and # subsequent line in master.cf. #mailbox_transport = cyrus # The fallback_transport specifies the optional transport in master.cf # to use for recipients that are not found in the UNIX passwd database. # This parameter has precedence over the luser_relay parameter. # # Specify a string of the form transport:nexthop, where transport is # the name of a mail delivery transport defined in master.cf. The # :nexthop part is optional. For more details see the sample transport # configuration file. # # NOTE: if you use this feature for accounts not in the UNIX password # file, then you must update the "local_recipient_maps" setting in # the main.cf file, otherwise the SMTP server will reject mail for # non-UNIX accounts with "User unknown in local recipient table". # #fallback_transport = lmtp:unix:/file/name #fallback_transport = cyrus #fallback_transport = # The luser_relay parameter specifies an optional destination address # for unknown recipients. By default, mail for unknown@$mydestination, # unknown@[$inet_interfaces] or unknown@[$proxy_interfaces] is returned # as undeliverable. # # The following expansions are done on luser_relay: $user (recipient # username), $shell (recipient shell), $home (recipient home directory), # $recipient (full recipient address), $extension (recipient address # extension), $domain (recipient domain), $local (entire recipient # localpart), $recipient_delimiter. Specify ${name?value} or # ${name:value} to expand value only when $name does (does not) exist. # # luser_relay works only for the default Postfix local delivery agent. # # NOTE: if you use this feature for accounts not in the UNIX password # file, then you must specify "local_recipient_maps =" (i.e. empty) in # the main.cf file, otherwise the SMTP server will reject mail for # non-UNIX accounts with "User unknown in local recipient table". # #luser_relay = $user@other.host #luser_relay = $local@other.host #luser_relay = admin+$local # JUNK MAIL CONTROLS # # The controls listed here are only a very small subset. The file # SMTPD_ACCESS_README provides an overview. # The header_checks parameter specifies an optional table with patterns # that each logical message header is matched against, including # headers that span multiple physical lines. # # By default, these patterns also apply to MIME headers and to the # headers of attached messages. With older Postfix versions, MIME and # attached message headers were treated as body text. # # For details, see "man header_checks". # #header_checks = regexp:$config_directory/header_checks # FAST ETRN SERVICE # # Postfix maintains per-destination logfiles with information about # deferred mail, so that mail can be flushed quickly with the SMTP # "ETRN domain.tld" command, or by executing "sendmail -qRdomain.tld". # See the ETRN_README document for a detailed description. # # The fast_flush_domains parameter controls what destinations are # eligible for this service. By default, they are all domains that # this server is willing to relay mail to. # #fast_flush_domains = $relay_domains # SHOW SOFTWARE VERSION OR NOT # # The smtpd_banner parameter specifies the text that follows the 220 # code in the SMTP server's greeting banner. Some people like to see # the mail version advertised. By default, Postfix shows no version. # # You MUST specify $myhostname at the start of the text. That is an # RFC requirement. Postfix itself does not care. # #smtpd_banner = $myhostname ESMTP $mail_name #smtpd_banner = $myhostname ESMTP $mail_name ($mail_version) # PARALLEL DELIVERY TO THE SAME DESTINATION # # How many parallel deliveries to the same user or domain? With local # delivery, it does not make sense to do massively parallel delivery # to the same user, because mailbox updates must happen sequentially, # and expensive pipelines in .forward files can cause disasters when # too many are run at the same time. With SMTP deliveries, 10 # simultaneous connections to the same domain could be sufficient to # raise eyebrows. # # Each message delivery transport has its XXX_destination_concurrency_limit # parameter. The default is $default_destination_concurrency_limit for # most delivery transports. For the local delivery agent the default is 2. #local_destination_concurrency_limit = 2 #default_destination_concurrency_limit = 20 # DEBUGGING CONTROL # # The debug_peer_level parameter specifies the increment in verbose # logging level when an SMTP client or server host name or address # matches a pattern in the debug_peer_list parameter. # debug_peer_level = 2 # The debug_peer_list parameter specifies an optional list of domain # or network patterns, /file/name patterns or type:name tables. When # an SMTP client or server host name or address matches a pattern, # increase the verbose logging level by the amount specified in the # debug_peer_level parameter. # #debug_peer_list = 127.0.0.1 #debug_peer_list = some.domain # The debugger_command specifies the external command that is executed # when a Postfix daemon program is run with the -D option. # # Use "command .. & sleep 5" so that the debugger can attach before # the process marches on. If you use an X-based debugger, be sure to # set up your XAUTHORITY environment variable before starting Postfix. # debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5 # If you can't use X, use this to capture the call stack when a # daemon crashes. The result is in a file in the configuration # directory, and is named after the process name and the process ID. # # debugger_command = # PATH=/bin:/usr/bin:/usr/local/bin; export PATH; (echo cont; # echo where) | gdb $daemon_directory/$process_name $process_id 2>&1 # >$config_directory/$process_name.$process_id.log & sleep 5 # # Another possibility is to run gdb under a detached screen session. # To attach to the screen session, su root and run "screen -r # " where uniquely matches one of the detached # sessions (from "screen -list"). # # debugger_command = # PATH=/bin:/usr/bin:/sbin:/usr/sbin; export PATH; screen # -dmS $process_name gdb $daemon_directory/$process_name # $process_id & sleep 1 # INSTALL-TIME CONFIGURATION INFORMATION # # The following parameters are used when installing a new Postfix version. # # sendmail_path: The full pathname of the Postfix sendmail command. # This is the Sendmail-compatible mail posting interface. # sendmail_path = /usr/local/sbin/sendmail # newaliases_path: The full pathname of the Postfix newaliases command. # This is the Sendmail-compatible command to build alias databases. # newaliases_path = /usr/local/bin/newaliases # mailq_path: The full pathname of the Postfix mailq command. This # is the Sendmail-compatible mail queue listing command. # mailq_path = /usr/local/bin/mailq # setgid_group: The group for mail submission and queue management # commands. This must be a group name with a numerical group ID that # is not shared with other accounts, not even with the Postfix account. # setgid_group = maildrop # html_directory: The location of the Postfix HTML documentation. # html_directory = /usr/local/share/doc/postfix # manpage_directory: The location of the Postfix on-line manual pages. # manpage_directory = /usr/local/man # sample_directory: The location of the Postfix sample configuration files. # This parameter is obsolete as of Postfix 2.1. # sample_directory = /usr/local/etc/postfix # readme_directory: The location of the Postfix README files. # readme_directory = /usr/local/share/doc/postfix inet_protocols = ipv4, ipv6 # sometimes comcast's IPv6 reverse DNS lookup stops working so you need to enable the line below (default: any) smtp_address_preference = ipv4 meta_directory = /usr/local/libexec/postfix shlib_directory = /usr/local/lib/postfix #additions below: # disable "new mail" notifications for local unix users biff = no # prevent spammers from searching for valid users disable_vrfy_command = yes # require properly formatted email addresses - prevents a lot of spam strict_rfc821_envelopes = yes # don't give any helpful info when a mailbox doesn't exist show_user_unknown_table_name = no # limit maximum e-mail size to 50MB. mailbox size must be at least as big as # the message size for the mail to be accepted, but has no meaning after # that since we are using Dovecot for delivery. message_size_limit = 51200000 mailbox_size_limit = 51200000 # require addresses of the form "user@domain.tld" allow_percent_hack = no swap_bangpath = no # path to the SSL certificate for the mail server smtpd_tls_cert_file = /mnt/certs/fullchain.pem smtpd_tls_key_file = /mnt/certs/privkeyr.pem # These two lines define how postfix will connect to other mail servers. # DANE is a stronger form of opportunistic TLS. You can read about it here: # http://www.postfix.org/TLS_README.html#client_tls_dane smtp_tls_security_level = dane smtp_dns_support_level = dnssec # DANE requires a DNSSEC capable resolver. If your DNS resolver doesn't # support DNSSEC, remove the above two lines and uncomment the below: # smtp_tls_security_level = may # Here we define the options for "mandatory" TLS. In our setup, TLS is only # "mandatory" for authenticating users. I got these settings from Mozilla's # SSL reccomentations page. # # NOTE: do not attempt to make TLS mandatory for all incoming/outgoing # connections. Do not attempt to change the default cipherlist for non- # mandatory connections either. There are still a lot of mail servers out # there that do not use TLS, and many that do only support old ciphers. # Forcing TLS for everyone *will* cause you to lose mail. smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, TLSv1.2 smtpd_tls_mandatory_ciphers = high tls_high_cipherlist = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256 # allow other mail servers to connect using TLS, but don't require it smtpd_tls_security_level = may # tickets and compression have known vulnerabilities tls_ssl_options = no_ticket, no_compression # it's more secure to generate your own DH params smtpd_tls_dh512_param_file = /mnt/certs/dhparam512.pem smtpd_tls_dh1024_param_file = /mnt/certs/dhparam2048.pem # cache incoming and outgoing TLS sessions smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_tlscache smtp_tls_session_cache_database = btree:${data_directory}/smtp_tlscache # enable SMTPD auth. Dovecot will place an `auth` socket in postfix's # runtime directory that we will use for authentication. smtpd_sasl_auth_enable = yes smtpd_sasl_path = private/auth smtpd_sasl_type = dovecot # only allow authentication over TLS smtpd_tls_auth_only = yes # don't allow plaintext auth methods on unencrypted connections smtpd_sasl_security_options = noanonymous, noplaintext # but plaintext auth is fine when using TLS smtpd_sasl_tls_security_options = noanonymous # add a message header when email was recieved over TLS smtpd_tls_received_header = yes # require that connecting mail servers identify themselves - this greatly # reduces spam smtpd_helo_required = yes # The following block specifies some security restrictions for incoming # mail. The gist of it is, authenticated users and connections from # localhost can do anything they want. Random people connecting over the # internet are treated with more suspicion: they must have a reverse DNS # entry and present a valid, FQDN HELO hostname. In addition, they can only # send mail to valid mailboxes on the server, and the sender's domain must # actually exist. smtpd_client_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_pipelining,reject_unknown_reverse_client_hostname # you might want to consider: # reject_unknown_client_hostname, # here. This will reject all incoming connections without a reverse DNS # entry that resolves back to the client's IP address. This is a very # restrictive check and may reject legitimate mail. smtpd_helo_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_invalid_helo_hostname,reject_unauth_pipelining,reject_non_fqdn_helo_hostname # you might want to consider: # reject_unknown_helo_hostname, # here. This will reject all incoming mail without a HELO hostname that # properly resolves in DNS. This is a somewhat restrictive check and may # reject legitimate mail. smtpd_sender_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_non_fqdn_sender,reject_unknown_sender_domain,reject_unauth_pipelining smtpd_relay_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination # !!! THE LAST SETTING PREVENTS YOU FROM BEING AN OPEN RELAY !!! # !!! DO NOT REMOVE IT UNDER ANY CIRCUMSTANCES !!! smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_non_fqdn_recipient,reject_unknown_recipient_domain,reject_unauth_pipelining,reject_unverified_recipient smtpd_data_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_multi_recipient_bounce,reject_unauth_pipelining # deliver mail for virtual users to Dovecot's LMTP socket virtual_transport = lmtp:unix:private/dovecot-lmtp # LDAP query to find which domains we accept mail for virtual_mailbox_domains = ldap:/usr/local/etc/postfix/ldap-virtual-mailbox-domains.cf # LDAP query to find which email addresses we accept mail for virtual_mailbox_maps = ldap:/usr/local/etc/postfix/ldap-virtual-mailbox-maps.cf #, hash:/usr/local/etc/postfix/system-virtual-mailboxes # LDAP query to find a user's email aliases virtual_alias_maps = ldap:/usr/local/etc/postfix/ldap-virtual-mailbox-alias-maps.cf, hash:/usr/local/etc/postfix/virtual-maillist-alias-maps # rspamd specific milter_protocol = 6 # if rspamd is down, don't reject mail milter_default_action = accept smtpd_milters = unix:/var/run/rspamd/milter.sock milter_mail_macros = i {mail_addr} {client_addr} {client_name} {auth_authen}