10 pmgconfig - Proxmox Mail Gateway Configuration Management Toolkit
16 include::pmgconfig.1-synopsis.adoc[]
23 Configuration Management
24 ========================
28 {pmg} is usually configured using the web-based Graphical User
29 Interface (GUI), but it is also possible to directly edit the
30 configuration files, use the REST API over 'https'
31 or the command line tool `pmgsh`.
33 The command line tool `pmgconfig` is used to simplify some common
34 configuration tasks, i.e. to generate cerificates and to rewrite
35 service configuration files.
37 NOTE: We use a Postgres database to store mail filter rules and
38 statistic data. See chapter xref:chapter_pmgdb[Database Management]
42 Configuration files overview
43 ----------------------------
45 `/etc/network/interfaces`::
47 Network setup. We never modify this files directly. Instead, we write
48 changes to `/etc/network/interfaces.new`. When you reboot, we rename
49 the file to `/etc/network/interfaces`, so any changes gets activated
54 DNS search domain and nameserver setup.
58 The system's host name.
62 Static table lookup for hostnames.
66 Stores common administration options, i.e. the spam and mail proxy setup.
68 `/etc/pmg/cluster.conf`::
74 The list of relay domains.
76 `/etc/pmg/dkim/domains`::
78 The list of domains for outbound DKIM signing.
80 `/etc/pmg/fetchmailrc`::
82 Fetchmail configuration (POP3 and IMAP setup).
84 `/etc/pmg/ldap.conf`::
88 `/etc/pmg/mynetworks`::
90 List of local (trusted) networks.
92 `/etc/pmg/subscription`::
94 Stores your subscription key and status.
96 `/etc/pmg/tls_policy`::
98 TLS policy for outbound connections.
100 `/etc/pmg/transports`::
102 Message delivery transport setup.
104 `/etc/pmg/user.conf`::
106 GUI user configuration.
108 `/etc/mail/spamassassin/custom.cf`::
110 Custom {spamassassin} setup.
112 `/etc/mail/spamassassin/pmg-scores.cf`::
114 Custom {spamassassin} rule scores.
116 Keys and Certificates
117 ---------------------
119 `/etc/pmg/pmg-api.pem`::
121 Key and certificate (combined) used be the HTTPs server (API).
123 `/etc/pmg/pmg-authkey.key`::
125 Privat key use to generate authentication tickets.
127 `/etc/pmg/pmg-authkey.pub`::
129 Public key use to verify authentication tickets.
131 `/etc/pmg/pmg-csrf.key`::
133 Internally used to generate CSRF tokens.
135 `/etc/pmg/pmg-tls.pem`::
137 Key and certificate (combined) to encrypt mail traffic (TLS).
139 `/etc/pmg/dkim/<selector>.private`::
141 Key for DKIM signing mails with selector '<selector>'.
144 [[pmgconfig_template_engine]]
145 Service Configuration Templates
146 -------------------------------
148 {pmg} uses various services to implement mail filtering, for example
149 the {postfix} Mail Transport Agent (MTA), the {clamav} antivirus
150 engine and the Apache {spamassassin} project. Those services use
151 separate configuration files, so we need to rewrite those files when
152 configuration is changed.
154 We use a template based approach to generate those files. The {tts} is
155 a well known, fast and flexible template processing system. You can
156 find the default templates in `/var/lib/pmg/templates/`. Please do not
157 modify them directly, because your modification would get lost on the
158 next update. Instead, copy the template you wish to change to
159 `/etc/pmg/templates/`, then apply your changes there.
161 Templates can access any configuration setting, and you can use the
162 `pmgconfig dump` command to get a list of all variable names:
167 dns.domain = yourdomain.tld
169 ipconfig.int_ip = 192.168.2.127
170 pmg.admin.advfilter = 1
174 The same tool is used to force regeneration of all template based
175 configuration files. You need to run that after modifying a template,
176 or when you directly edit configuration files
179 # pmgconfig sync --restart 1
182 The above command also restarts services if the underlying configuration
183 files are changed. Please note that this is automatically done when
184 you change the configuration using the GUI or API.
186 NOTE: Modified templates from `/etc/pmg/templates/` are automatically
187 synced from the master node to all cluster members.
190 [[pmgconfig_systemconfig]]
198 [thumbnail="pmg-gui-network-config.png", big=1]
201 Normally the network and time is already configured when you visit the
202 GUI. The installer asks for those settings and sets up the correct
205 The default setup uses a single Ethernet adapter and static IP
206 assignment. The configuration is stored at '/etc/network/interfaces',
207 and the actual network setup is done the standard Debian way using
210 .Example network setup '/etc/network/interfaces'
212 source /etc/network/interfaces.d/*
215 iface lo inet loopback
218 iface ens18 inet static
219 address 192.168.2.127
220 netmask 255.255.240.0
226 Many tests to detect SPAM mails use DNS queries, so it is important to
227 have a fast and reliable DNS server. We also query some public
228 available DNS Blacklists. Most of them apply rate limits for clients,
229 so they simply will not work if you use a public DNS server (because
230 they are usually blocked). We recommend to use your own DNS server,
231 which need to be configured in 'recursive' mode.
238 [thumbnail="pmg-gui-system-options.png", big=1]
242 Those settings are saved to subsection 'admin' in `/etc/pmg/pmg.conf`,
243 using the following configuration keys:
245 include::pmg.admin-conf-opts.adoc[]
248 Mail Proxy Configuration
249 ------------------------
251 [[pmgconfig_mailproxy_relaying]]
256 [thumbnail="pmg-gui-mailproxy-relaying.png", big=1]
259 Those settings are saved to subsection 'mail' in `/etc/pmg/pmg.conf`,
260 using the following configuration keys:
262 include::pmg.mail-relaying-conf-opts.adoc[]
264 [[pmgconfig_mailproxy_relay_domains]]
269 [thumbnail="pmg-gui-mailproxy-relaydomains.png", big=1]
272 List of relayed mail domains, i.e. what destination domains this
273 system will relay mail to. The system will reject incoming mails to
277 [[pmgconfig_mailproxy_ports]]
282 [thumbnail="pmg-gui-mailproxy-ports.png", big=1]
285 Those settings are saved to subsection 'mail' in `/etc/pmg/pmg.conf`,
286 using the following configuration keys:
288 include::pmg.mail-ports-conf-opts.adoc[]
291 [[pmgconfig_mailproxy_options]]
296 [thumbnail="pmg-gui-mailproxy-options.png", big=1]
299 Those settings are saved to subsection 'mail' in `/etc/pmg/pmg.conf`,
300 using the following configuration keys:
302 include::pmg.mail-options-conf-opts.adoc[]
305 [[pmgconfig_mailproxy_before_after_queue]]
306 Before and After Queue scanning
307 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
309 Scanning email can happen at two different stages of mail-processing:
311 * During the SMTP Session after the complete message has been received (after
312 the 'DATA' command), known as 'before queue filtering'.
314 * After intially accepting the mail and putting it on a queue for further
315 processing, known as 'after queue filtering'.
317 The former has the advantage that the system can reject a mail (by sending a
318 permanent reject code '554'), and leave the task of notifying the original
319 sender to the other mailserver. This is of particular advantage if the
320 processed mail is a spam message or contains a virus and has a forged
321 sender-address. Sending out a notification in this situation leads so-called
322 'backscatter' mail, which might cause your server to get listed as spamming on
325 The latter has the advantage of providing faster delivery of mails for the
326 sending servers, since queueing mails is much faster than analyzing it for
329 If a mail is addressed to multiple recipients (e.g. when multiple addresses are
330 subscribed to the same mailinglist) the situation is more complicated: Your
331 mailserver can only reject or accept the mail for all recipients, after having
332 received the complete message, while your rule setup might accept the mail for
333 part of the recipients and reject it for others. This can be due to a
334 complicated rule setup, or if your users use the 'User White- and Blacklist'
337 If the resulting action of the rule system is the same for all recipients {pmg}
338 responds accordingly if configured for before queue filtering (sending '554'
339 for a blocked mail and '250' for an accepted or quarantined mail). If some
340 mailboxes accept the mail and some reject it the system has to accept the mail.
342 Whether {pmg} notifies the sender that delivery failed for some recipients by
343 sending a non-delivery report, depends on the 'ndr_on_block' setting in
344 '/etc/pmg/pmg.conf'. If enabled an NDR is sent. Keeping it disabled prevents
345 NDRs being sent to the (possibly forged) sender and thus minimizes the chance
346 of getting your IP listed on a RBL. However in certain environments it can be
347 unacceptable not to inform the sender about a rejected mail.
349 The setting has the same effect if after queue filtering is configured, with
350 the exception that an NDR is always sent out, even if all recipients block the
351 mail, since the mail already got accepted before being analyzed.
353 The details of integrating the mail proxy with {postfix} in both setups are
354 explained in {postfix_beforequeue} and {postfix_afterqueue} respectively.
356 NOTE: Since before queue filtering is currently incompatible with the
357 'Tracking Center' you need to enable it by manually
358 editing '/etc/pmg/pmg.conf'.
361 [[pmgconfig_mailproxy_transports]]
366 [thumbnail="pmg-gui-mailproxy-transports.png", big=1]
369 You can use {pmg} to send e-mails to different internal
370 e-mail servers. For example you can send e-mails addressed to
371 domain.com to your first e-mail server, and e-mails addressed to
372 subdomain.domain.com to a second one.
374 You can add the IP addresses, hostname, transport protocol (smtp/lmtp),
375 transport ports and mail domains (or just single email addresses)
376 of your additional e-mail servers. When transport protocol is set to `lmtp`,
377 the option 'Use MX' is useless and will be automatically set to 'No'.
380 [[pmgconfig_mailproxy_networks]]
385 [thumbnail="pmg-gui-mailproxy-networks.png", big=1]
388 You can add additional internal (trusted) IP networks or hosts.
389 All hosts in this list are allowed to relay.
391 NOTE: Hosts in the same subnet with Proxmox can relay by default and
392 it’s not needed to add them in this list.
395 [[pmgconfig_mailproxy_tls]]
400 [thumbnail="pmg-gui-mailproxy-tls.png", big=1]
403 Transport Layer Security (TLS) provides certificate-based
404 authentication and encrypted sessions. An encrypted session protects
405 the information that is transmitted with SMTP mail. When you activate
406 TLS, {pmg} automatically generates a new self signed
407 certificate for you (`/etc/pmg/pmg-tls.pem`).
409 {pmg} uses opportunistic TLS encryption by default. The SMTP transaction is
410 encrypted if the 'STARTTLS' ESMTP feature is supported by the remote
411 server. Otherwise, messages are sent in the clear.
413 You can set a different TLS policy per destination. A destination is either a
414 remote domain or a next-hop destination as specified in `/etc/pmg/transport`.
415 This can be used, should you need to prevent e-mail delivery without
416 encryption, or to work around a broken 'STARTTLS' ESMTP implementation. See
417 {postfix_tls_readme} for details on the supported policies.
421 To get additional information about SMTP TLS activity you can enable
422 TLS logging. That way information about TLS sessions and used
423 certificate’s is logged via syslog.
425 Add TLS received header::
427 Set this option to include information about the protocol and cipher
428 used as well as the client and issuer CommonName into the "Received:"
431 Those settings are saved to subsection 'mail' in `/etc/pmg/pmg.conf`,
432 using the following configuration keys:
434 include::pmg.mail-tls-conf-opts.adoc[]
437 [[pmgconfig_mailproxy_dkim]]
442 [thumbnail="pmg-gui-mailproxy-dkim.png", big=1]
445 DomainKeys Identified Mail (DKIM) Signatures (see {dkim_rfc}) is a method to
446 cryptographically authenticate a mail as originating from a particular domain.
447 Before sending the mail a hash over certain header fields and the body is
448 computed, signed with a private key and added in the `DKIM-Signature` header of
449 the mail. The 'selector' (a short identifier chosen by you, used to identify
450 which system and private key were used for signing) is also included in the
451 `DKIM-Signature` header.
453 The verification is done by the receiver: The public key is fetched
454 via DNS TXT lookup for `yourselector._domainkey.yourdomain.example` and used
455 for verifying the hash. You can publish multiple selectors for your domain,
456 each use by a system which sends e-mail from your domain, without the need to
457 share the private key.
459 {pmg} verifies DKIM Signatures for inbound mail in the Spam Filter by default.
461 Additionally it supports conditionally signing outbound mail if configured.
462 It uses one private key and selector per PMG deployment (all nodes in a cluster
463 use the same key). The key has a minimal size of 1024 bits and rsa-sha256 is
464 used as signing algorithm.
466 The headers included in the signature are taken from the list of
467 `Mail::DKIM::Signer`. Additionally `Content-Type` (if present), `From`, `To`,
468 `CC`, `Reply-To` and `Subject` get oversigned.
470 You can either sign all mails received on the internal port using the domain of
471 the envelope sender address or create a list of domains, for which e-mails
472 should be signed, defaulting to the list of relay domains.
475 Enable DKIM Signing::
477 Controls whether outbound mail should get DKIM signed.
481 The selector used for signing the mail. The private key used for signing is
482 saved under `/etc/pmg/dkim/yourselector.private`. You can display the DNS TXT
483 record which you need to add to all domains signed by {pmg} by clicking on the
484 'View DNS Record' Button.
486 Sign all Outgoing Mail::
488 Controls whether all outbound mail should get signed or only mails from domains
489 listed in `/etc/pmg/dkim/domains` if it exists and `/etc/pmg/domains` otherwise.
491 Those settings are saved to subsection 'admin' in `/etc/pmg/pmg.conf`,
492 using the following configuration keys:
494 include::pmg.admin-dkim-conf-opts.adoc[]
501 [thumbnail="pmg-gui-mailproxy-whitelist.png", big=1]
504 All SMTP checks are disabled for those entries (e. g. Greylisting,
507 NOTE: If you use a backup MX server (e.g. your ISP offers this service
508 for you) you should always add those servers here.
511 [[pmgconfig_spamdetector]]
512 Spam Detector Configuration
513 ---------------------------
519 [thumbnail="pmg-gui-spam-options.png", big=1]
522 {pmg} uses a wide variety of local and network tests to identify spam
523 signatures. This makes it harder for spammers to identify one aspect
524 which they can craft their messages to work around the spam filter.
526 Every single e-mail will be analyzed and gets a spam score
527 assigned. The system attempts to optimize the efficiency of the rules
528 that are run in terms of minimizing the number of false positives and
531 include::pmg.spam-conf-opts.adoc[]
534 [[pmgconfig_spamdetector_quarantine]]
539 [thumbnail="pmg-gui-spamquar-options.png", big=1]
542 Proxmox analyses all incoming e-mail messages and decides for each
543 e-mail if its ham or spam (or virus). Good e-mails are delivered to
544 the inbox and spam messages can be moved into the spam quarantine.
546 The system can be configured to send daily reports to inform users
547 about the personal spam messages received the last day. That report is
548 only sent if there are new messages in the quarantine.
550 Some options are only available in the config file `/etc/pmg/pmg.conf`,
551 and not in the webinterface.
553 include::pmg.spamquar-conf-opts.adoc[]
556 [[pmgconfig_spamdetector_customscores]]
557 Customization of Rulescores
558 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
561 [thumbnail="pmg-gui-spam-custom-scores.png", big=1]
564 While the default scoring of {spamassassin}'s ruleset provides very good
565 detection rates, sometimes your particular environment can benefit from
566 slightly adjusting the score of a particular rule. Two examples:
568 * Your system receives spam mails which are scored at 4.9 and you have
569 a rule which puts all mails above 5 in the quarantine. The one thing the
570 spam mails have in common is that they all hit 'URIBL_BLACK'. By increasing
571 the score of this rule by 0.2 points the spam mails would all be quarantined
572 instead of being sent to your users
574 * Your system tags many legitimate mails from a partner organization as spam,
575 because the organization has a policy that each mail has to start with
576 'Dear madam or sir' (generating 1.9 points through the rule
577 'DEAR_SOMETHING'). By setting the score of this rule to 0 you can disable
580 The system logs all rules which particular mail hits. Analyzing the logs can
581 lead to finding such a pattern in your environment.
583 You can adjust the score of a rule by creating a new 'Custom Rule Score' entry
586 NOTE: In general it is strongly recommended to not make large changes to the
591 Virus Detector Configuration
592 ----------------------------
594 [[pmgconfig_clamav_options]]
599 [thumbnail="pmg-gui-virus-options.png", big=1]
602 All mails are automatically passed to the included virus detector
603 ({clamav}). The default setting are considered safe, so it is usually
604 not required to change them.
606 {clamav} related settings are saved to subsection 'clamav' in `/etc/pmg/pmg.conf`,
607 using the following configuration keys:
609 include::pmg.clamav-conf-opts.adoc[]
612 [thumbnail="pmg-gui-clamav-database.png", big=1]
615 Please note that the virus signature database it automatically
616 updated. But you can see the database status on the GUI, and you can
617 trigger manual updates there.
620 [[pmgconfig_clamav_quarantine]]
625 [thumbnail="pmg-gui-virusquar-options.png", big=1]
628 Indentified virus mails are automatically moved to the virus
629 quarantine. The administartor can view those mails using the GUI, or
630 deliver them in case of false positives. {pmg} does not notify
631 individual users about received virus mails.
633 Virus quarantine related settings are saved to subsection 'virusquar'
634 in `/etc/pmg/pmg.conf`, using the following configuration keys:
636 include::pmg.virusquar-conf-opts.adoc[]
639 Custom SpamAssassin configuration
640 ---------------------------------
642 This is only for advanced users. {spamassassin}'s rules and their associated
643 scores get updated regularly and are trained on a huge corpus, which gets
644 classified by experts. In most cases adding a rule for matching a particular
645 keyword is the wrong approach, leading to many false positives. Usually bad
646 detection rates are better addressed by properly setting up DNS than by adding
647 a custom rule - watch out for matches to 'URIBL_BLOCKED' in the logs or
648 spam-headers - see the {spamassassin_dnsbl}.
650 To add or change the Proxmox {spamassassin} configuration please login to the
651 console via SSH. Change to the `/etc/mail/spamassassin/` directory. In this
652 directory there are several files (`init.pre`, `local.cf`, ...) - do not change
653 them, as `init.pre`, `v310.pre`, `v320.pre`, `local.cf` will be overwritten by
654 the xref:pmgconfig_template_engine[template engine], while the others can
655 get updated by any {spamassassin} package upgrade.
657 To add your special configuration, you have to create a new file and name it
658 `custom.cf` (in this directory), then add your configuration there. Make sure
659 to use the correct {spamassassin} syntax, and test with
662 # spamassassin -D --lint
665 If you run a cluster, the `custom.cf` file is synchronized from the
666 master node to all cluster members automatically.
668 Should you only wish to adjust the score assigned to a particular rule you
669 can also use the xref:pmgconfig_spamdetector_customscores[Custom Rule Score]
673 [[pmgconfig_custom_check]]
674 Custom Check Interface
675 ----------------------
677 For use cases which are not handled by the {pmg} Virus Detector and
678 {spamassassin} configuration, advanced users can create a custom check
679 executable which, if enabled will be called before the Virus Detector and before
680 passing an e-mail through the Rule System. The custom check API is kept as
681 simple as possible, while still providing a great deal of control over the
682 treatment of an e-mail. Its input is passed via two CLI arguments:
684 * the 'api-version' (currently `v1`) - for potential future change of the
687 * the 'queue-file-name' - a filename, which contains the complete e-mail as
690 The expected output need to be printed on STDOUT and consists of two lines:
692 * the 'api-version' (currently 'v1') - see above
694 * one of the following 3 results:
695 ** 'OK' - e-mail is ok
696 ** 'VIRUS: <virusdescription>' - e-mail is treated as if it contained a virus
697 (the virusdescription is logged and added to the e-mail's headers)
698 ** 'SCORE: <number>' - <number> is added (negative numbers are also possible)
699 to the e-mail's spamscore
701 The check is run with a 5 minute timeout - if it is exceeded the check
702 executable is killed and the e-mail is treated as OK.
704 All output written to STDERR by the check is written with priority 'err' to the
707 A simple sample script following the API (and yielding a random result) for
713 echo "called with $*" 1>&2
715 if [ "$#" -ne 2 ]; then
716 echo "usage: $0 APIVERSION QUEUEFILENAME" 1>&2
723 if [ "$apiver" != "v1" ]; then
724 echo "wrong APIVERSION: $apiver" 1>&2
732 choice=$(shuf -i 0-3 -n1)
742 echo VIRUS: Random Virus
745 for i in $(seq 1 7); do
746 echo "custom checking mail: $queue_file - minute $i" 1>&2
755 The custom check needs to be enabled in the admin section of `/etc/pmg/pmg.conf`
762 The location of the custom check executable can also be set there with the key
763 `custom_check_path` and defaults to `/usr/local/bin/pmg-custom-check`.
769 User management in {pmg} consists of three types of users/accounts:
772 [[pmgconfig_localuser]]
776 [thumbnail="pmg-gui-local-user-config.png", big=1]
778 Local users are used to manage and audit {pmg}. Those users can login on the
779 management web interface.
781 There are three roles:
785 Is allowed to manage settings of {pmg}, except some tasks like
786 network configuration and upgrading.
790 Is allowed to manage quarantines, blacklists and whitelists, but not other
791 settings. Has no right to view any other data.
795 With this role, the user is only allowed to view data and configuration, but
798 In addition there is always the 'root' user, which is used to perform special
799 system administrator tasks, such as updgrading a host or changing the
800 network configuration.
802 NOTE: Only pam users are able to login via the webconsole and ssh, which the
803 users created with the web interface are not. Those users are created for
804 {pmg} administration only.
806 Local user related settings are saved in `/etc/pmg/user.conf`.
808 For details of the fields see xref:pmg_user_configuration_file[user.conf]
811 LDAP/Active Directory
812 ~~~~~~~~~~~~~~~~~~~~~
814 [thumbnail="pmg-gui-ldap-user-config.png", big=1]
816 You can specify multiple LDAP/Active Directory profiles, so that you can
817 create rules matching those users and groups.
819 Creating a profile requires (at least) the following:
822 * protocol (LDAP or LDAPS; LDAPS is recommended)
823 * at least one server
824 * a user and password (if your server does not support anonymous binds)
826 All other fields should work with the defaults for most setups, but can be
827 used to customize the queries.
829 The settings are saved to `/etc/pmg/ldap.conf`. Details for the options
830 can be found here: xref:pmg_ldap_configuration_file[ldap.conf]
835 It is highly recommended that the user which you use for connecting to the
836 LDAP server only has the permission to query the server. For LDAP servers
837 (for example OpenLDAP or FreeIPA), the username has to be of a format like
838 'uid=username,cn=users,cn=accounts,dc=domain' , where the specific fields are
839 depending on your setup. For Active Directory servers, the format should be
840 like 'username@domain' or 'domain\username'.
845 {pmg} synchronizes the relevant user and group info periodically, so that
846 that information is available in a fast manner, even when the LDAP/AD server
847 is temporarily not accessible.
849 After a successfull sync, the groups and users should be visible on the web
850 interface. After that, you can create rules targeting LDAP users and groups.
853 [[pmgconfig_fetchmail]]
857 [thumbnail="pmg-gui-fetchmail-config.png", big=1]
859 Fetchmail is utility for polling and forwarding e-mails. You can define
860 e-mail accounts, which will then be fetched and forwarded to the e-mail
863 You have to add an entry for each account/target combination you want to
864 fetch and forward. Those will then be regularly polled and forwarded,
865 according to your configuration.
867 The API and web interface offer following configuration options:
869 include::fetchmail.conf.5-opts.adoc[]
873 include::pmg-copyright.adoc[]