NAME

pmgconfig - Proxmox Mail Gateway Configuration Management Toolkit

SYNOPSIS

pmgconfig <COMMAND> [ARGS] [OPTIONS]

pmgconfig apicert [OPTIONS]

Generate /etc/pmg/pmg-api.pem (self signed certificate for GUI and REST API).

--force <boolean> (default = 0)

Overwrite existing certificate.

pmgconfig dkim_record

Get the public key for the configured selector, prepared as DKIM TXT record

pmgconfig dkim_set --keysize <integer> --selector <string> [OPTIONS]

Generate a new private key for selector. All future mail will be signed with the new key!

--force <boolean>

Overwrite existing key

--keysize <integer> (1024 - N)

Number of bits for the RSA-Key

--selector <string>

DKIM Selector

pmgconfig dump

Print configuration setting which can be used in templates.

pmgconfig help [OPTIONS]

Get help about specified command.

--extra-args <array>

Shows help for a specific command

--verbose <boolean>

Verbose output format.

pmgconfig init

Generate required files in /etc/pmg/

pmgconfig ldapsync

Syncronize the LDAP database.

pmgconfig sync [OPTIONS]

Syncronize Proxmox Mail Gateway configurations with system configuration.

--restart <boolean> (default = 0)

Restart services if necessary.

pmgconfig tlscert [OPTIONS]

Generate /etc/pmg/pmg-tls.pem (self signed certificate for encrypted SMTP traffic).

--force <boolean> (default = 0)

Overwrite existing certificate.

DESCRIPTION

Proxmox Mail Gateway is usually configured using the web-based Graphical User Interface (GUI), but it is also possible to directly edit the configuration files, use the REST API over https or the command line tool pmgsh.

The command line tool pmgconfig is used to simplify some common configuration tasks, i.e. to generate cerificates and to rewrite service configuration files.

Note We use a Postgres database to store mail filter rules and statistic data. See chapter Database Management for more information.

Configuration files overview

/etc/network/interfaces

Network setup. We never modify this files directly. Instead, we write changes to /etc/network/interfaces.new. When you reboot, we rename the file to /etc/network/interfaces, so any changes gets activated on the next reboot.

/etc/resolv.conf

DNS search domain and nameserver setup.

/etc/hostname

The system’s host name.

/etc/hosts

Static table lookup for hostnames.

/etc/pmg/pmg.conf

Stores common administration options, i.e. the spam and mail proxy setup.

/etc/pmg/cluster.conf

The cluster setup.

/etc/pmg/domains

The list of relay domains.

/etc/pmg/dkim/domains

The list of domains for outbound DKIM signing.

/etc/pmg/fetchmailrc

Fetchmail configuration (POP3 and IMAP setup).

/etc/pmg/ldap.conf

LDAP configuration.

/etc/pmg/mynetworks

List of local (trusted) networks.

/etc/pmg/subscription

Stores your subscription key and status.

/etc/pmg/tls_policy

TLS policy for outbound connections.

/etc/pmg/transports

Message delivery transport setup.

/etc/pmg/user.conf

GUI user configuration.

/etc/mail/spamassassin/custom.cf

Custom SpamAssassin™ setup.

/etc/mail/spamassassin/pmg-scores.cf

Custom SpamAssassin™ rule scores.

Keys and Certificates

/etc/pmg/pmg-api.pem

Key and certificate (combined) used be the HTTPs server (API).

/etc/pmg/pmg-authkey.key

Privat key use to generate authentication tickets.

/etc/pmg/pmg-authkey.pub

Public key use to verify authentication tickets.

/etc/pmg/pmg-csrf.key

Internally used to generate CSRF tokens.

/etc/pmg/pmg-tls.pem

Key and certificate (combined) to encrypt mail traffic (TLS).

/etc/pmg/dkim/<selector>.private

Key for DKIM signing mails with selector <selector>.

Service Configuration Templates

Proxmox Mail Gateway uses various services to implement mail filtering, for example the Postfix Mail Transport Agent (MTA), the ClamAV® antivirus engine and the Apache SpamAssassin™ project. Those services use separate configuration files, so we need to rewrite those files when configuration is changed.

We use a template based approach to generate those files. The Template Toolkit is a well known, fast and flexible template processing system. You can find the default templates in /var/lib/pmg/templates/. Please do not modify them directly, because your modification would get lost on the next update. Instead, copy the template you wish to change to /etc/pmg/templates/, then apply your changes there.

Templates can access any configuration setting, and you can use the pmgconfig dump command to get a list of all variable names:

# pmgconfig dump
...
dns.domain = yourdomain.tld
dns.hostname = pmg
ipconfig.int_ip = 192.168.2.127
pmg.admin.advfilter = 1
...

The same tool is used to force regeneration of all template based configuration files. You need to run that after modifying a template, or when you directly edit configuration files

# pmgconfig sync --restart 1

The above command also restarts services if the underlying configuration files are changed. Please note that this is automatically done when you change the configuration using the GUI or API.

Note Modified templates from /etc/pmg/templates/ are automatically synced from the master node to all cluster members.

System Configuration

Network and Time

Normally the network and time is already configured when you visit the GUI. The installer asks for those settings and sets up the correct values.

The default setup uses a single Ethernet adapter and static IP assignment. The configuration is stored at /etc/network/interfaces, and the actual network setup is done the standard Debian way using package ifupdown.

Example network setup /etc/network/interfaces
source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

auto ens18
iface ens18 inet static
        address  192.168.2.127
        netmask  255.255.240.0
        gateway  192.168.2.1
DNS recommendations

Many tests to detect SPAM mails use DNS queries, so it is important to have a fast and reliable DNS server. We also query some public available DNS Blacklists. Most of them apply rate limits for clients, so they simply will not work if you use a public DNS server (because they are usually blocked). We recommend to use your own DNS server, which need to be configured in recursive mode.

Options

Those settings are saved to subsection admin in /etc/pmg/pmg.conf, using the following configuration keys:

advfilter: <boolean> (default = 1)

Use advanced filters for statistic.

avast: <boolean> (default = 0)

Use Avast Virus Scanner (/usr/bin/scan). You need to buy and install Avast Core Security before you can enable this feature.

clamav: <boolean> (default = 1)

Use ClamAV Virus Scanner. This is the default virus scanner and is enabled by default.

custom_check: <boolean> (default = 0)

Use Custom Check Script. The script has to take the defined arguments and can return Virus findings or a Spamscore.

custom_check_path: ^/([^/\0]+\/)+[^/\0]+$ (default = /usr/local/bin/pmg-custom-check)

Absolute Path to the Custom Check Script

dailyreport: <boolean> (default = 1)

Send daily reports.

demo: <boolean> (default = 0)

Demo mode - do not start SMTP filter.

dkim_selector: <string>

Default DKIM selector

dkim_sign: <boolean> (default = 0)

DKIM sign outbound mails with the configured Selector.

dkim_sign_all_mail: <boolean> (default = 0)

DKIM sign all outgoing mails irrespective of the Envelope From domain.

email: <string> (default = admin@domain.tld)

Administrator E-Mail address.

http_proxy: http://.*

Specify external http proxy which is used for downloads (example: http://username:password@host:port/)

statlifetime: <integer> (1 - N) (default = 7)

User Statistics Lifetime (days)

Mail Proxy Configuration

Relaying

Those settings are saved to subsection mail in /etc/pmg/pmg.conf, using the following configuration keys:

relay: <string>

The default mail delivery transport (incoming mails).

relaynomx: <boolean> (default = 0)

Disable MX lookups for default relay (SMTP only, ignored for LMTP).

relayport: <integer> (1 - 65535) (default = 25)

SMTP/LMTP port number for relay host.

relayprotocol: <lmtp | smtp> (default = smtp)

Transport protocol for relay host.

smarthost: <string>

When set, all outgoing mails are deliverd to the specified smarthost.

smarthostport: <integer> (1 - 65535) (default = 25)

SMTP port number for smarthost.

Relay Domains

List of relayed mail domains, i.e. what destination domains this system will relay mail to. The system will reject incoming mails to other domains.

Ports

Those settings are saved to subsection mail in /etc/pmg/pmg.conf, using the following configuration keys:

ext_port: <integer> (1 - 65535) (default = 25)

SMTP port number for incoming mail (untrusted). This must be a different number than int_port.

int_port: <integer> (1 - 65535) (default = 26)

SMTP port number for outgoing mail (trusted).

Options

Those settings are saved to subsection mail in /etc/pmg/pmg.conf, using the following configuration keys:

banner: <string> (default = ESMTP Proxmox)

ESMTP banner.

before_queue_filtering: <boolean> (default = 0)

Enable before queue filtering by pmg-smtp-filter

conn_count_limit: <integer> (0 - N) (default = 50)

How many simultaneous connections any client is allowed to make to this service. To disable this feature, specify a limit of 0.

conn_rate_limit: <integer> (0 - N) (default = 0)

The maximal number of connection attempts any client is allowed to make to this service per minute. To disable this feature, specify a limit of 0.

dnsbl_sites: <string>

Optional list of DNS white/blacklist domains (see postscreen_dnsbl_sites parameter).

dnsbl_threshold: <integer> (0 - N) (default = 1)

The inclusive lower bound for blocking a remote SMTP client, based on its combined DNSBL score (see postscreen_dnsbl_threshold parameter).

dwarning: <integer> (0 - N) (default = 4)

SMTP delay warning time (in hours).

greylist: <boolean> (default = 1)

Use Greylisting.

helotests: <boolean> (default = 0)

Use SMTP HELO tests.

hide_received: <boolean> (default = 0)

Hide received header in outgoing mails.

maxsize: <integer> (1024 - N) (default = 10485760)

Maximum email size. Larger mails are rejected.

message_rate_limit: <integer> (0 - N) (default = 0)

The maximal number of message delivery requests that any client is allowed to make to this service per minute.To disable this feature, specify a limit of 0.

ndr_on_block: <boolean> (default = 0)

Send out NDR when mail gets blocked

rejectunknown: <boolean> (default = 0)

Reject unknown clients.

rejectunknownsender: <boolean> (default = 0)

Reject unknown senders.

spf: <boolean> (default = 1)

Use Sender Policy Framework.

verifyreceivers: <450 | 550>

Enable receiver verification. The value spefifies the numerical reply code when the Postfix SMTP server rejects a recipient address.

Before and After Queue scanning

Scanning email can happen at two different stages of mail-processing:

  • During the SMTP Session after the complete message has been received (after the DATA command), known as before queue filtering.

  • After intially accepting the mail and putting it on a queue for further processing, known as after queue filtering.

The former has the advantage that the system can reject a mail (by sending a permanent reject code 554), and leave the task of notifying the original sender to the other mailserver. This is of particular advantage if the processed mail is a spam message or contains a virus and has a forged sender-address. Sending out a notification in this situation leads so-called backscatter mail, which might cause your server to get listed as spamming on RBLs.

The latter has the advantage of providing faster delivery of mails for the sending servers, since queueing mails is much faster than analyzing it for spam and viruses.

If a mail is addressed to multiple recipients (e.g. when multiple addresses are subscribed to the same mailinglist) the situation is more complicated: Your mailserver can only reject or accept the mail for all recipients, after having received the complete message, while your rule setup might accept the mail for part of the recipients and reject it for others. This can be due to a complicated rule setup, or if your users use the User White- and Blacklist feature.

If the resulting action of the rule system is the same for all recipients Proxmox Mail Gateway responds accordingly if configured for before queue filtering (sending 554 for a blocked mail and 250 for an accepted or quarantined mail). If some mailboxes accept the mail and some reject it the system has to accept the mail.

Whether Proxmox Mail Gateway notifies the sender that delivery failed for some recipients by sending a non-delivery report, depends on the ndr_on_block setting in /etc/pmg/pmg.conf. If enabled an NDR is sent. Keeping it disabled prevents NDRs being sent to the (possibly forged) sender and thus minimizes the chance of getting your IP listed on a RBL. However in certain environments it can be unacceptable not to inform the sender about a rejected mail.

The setting has the same effect if after queue filtering is configured, with the exception that an NDR is always sent out, even if all recipients block the mail, since the mail already got accepted before being analyzed.

The details of integrating the mail proxy with Postfix in both setups are explained in Postfix Before-Queue Content Filter and Postfix After-Queue Content Filter respectively.

Note Since before queue filtering is currently incompatible with the Tracking Center you need to enable it by manually editing /etc/pmg/pmg.conf.

Transports

You can use Proxmox Mail Gateway to send e-mails to different internal e-mail servers. For example you can send e-mails addressed to domain.com to your first e-mail server, and e-mails addressed to subdomain.domain.com to a second one.

You can add the IP addresses, hostname, transport protocol (smtp/lmtp), transport ports and mail domains (or just single email addresses) of your additional e-mail servers. When transport protocol is set to lmtp, the option Use MX is useless and will be automatically set to No.

Networks

You can add additional internal (trusted) IP networks or hosts. All hosts in this list are allowed to relay.

Note Hosts in the same subnet with Proxmox can relay by default and it’s not needed to add them in this list.

TLS

Transport Layer Security (TLS) provides certificate-based authentication and encrypted sessions. An encrypted session protects the information that is transmitted with SMTP mail. When you activate TLS, Proxmox Mail Gateway automatically generates a new self signed certificate for you (/etc/pmg/pmg-tls.pem).

Proxmox Mail Gateway uses opportunistic TLS encryption by default. The SMTP transaction is encrypted if the STARTTLS ESMTP feature is supported by the remote server. Otherwise, messages are sent in the clear. You can set a different TLS policy per desitination domain, should you for example need to prevent e-mail delivery without encryption, or to work around a broken STARTTLS ESMTP implementation. See Postfix TLS Readme for details on the supported policies.

Enable TLS logging

To get additional information about SMTP TLS activity you can enable TLS logging. That way information about TLS sessions and used certificate’s is logged via syslog.

Add TLS received header

Set this option to include information about the protocol and cipher used as well as the client and issuer CommonName into the "Received:" message header.

Those settings are saved to subsection mail in /etc/pmg/pmg.conf, using the following configuration keys:

tls: <boolean> (default = 0)

Enable TLS.

tlsheader: <boolean> (default = 0)

Add TLS received header.

tlslog: <boolean> (default = 0)

Enable TLS Logging.

DKIM Signing

DomainKeys Identified Mail (DKIM) Signatures (see RFC 6376) is a method to cryptographically authenticate a mail as originating from a particular domain. Before sending the mail a hash over certain header fields and the body is computed, signed with a private key and added in the DKIM-Signature header of the mail. The selector (a short identifier chosen by you, used to identify which system and private key were used for signing) is also included in the DKIM-Signature header.

The verification is done by the receiver: The public key is fetched via DNS TXT lookup for yourselector._domainkey.yourdomain.example and used for verifying the hash. You can publish multiple selectors for your domain, each use by a system which sends e-mail from your domain, without the need to share the private key.

Proxmox Mail Gateway verifies DKIM Signatures for inbound mail in the Spam Filter by default.

Additionally it supports conditionally signing outbound mail if configured. It uses one private key and selector per PMG deployment (all nodes in a cluster use the same key). The key has a minimal size of 1024 bits and rsa-sha256 is used as signing algorithm.

The headers included in the signature are taken from the list of Mail::DKIM::Signer. Additionally Content-Type (if present), From, To, CC, Reply-To and Subject get oversigned.

You can either sign all mails received on the internal port using the domain of the envelope sender address or create a list of domains, for which e-mails should be signed, defaulting to the list of relay domains.

Enable DKIM Signing

Controls whether outbound mail should get DKIM signed.

Selector

The selector used for signing the mail. The private key used for signing is saved under /etc/pmg/dkim/yourselector.private. You can display the DNS TXT record which you need to add to all domains signed by Proxmox Mail Gateway by clicking on the View DNS Record Button.

Sign all Outgoing Mail

Controls whether all outbound mail should get signed or only mails from domains listed in /etc/pmg/dkim/domains if it exists and /etc/pmg/domains otherwise.

Those settings are saved to subsection admin in /etc/pmg/pmg.conf, using the following configuration keys:

dkim_selector: <string>

Default DKIM selector

dkim_sign: <boolean> (default = 0)

DKIM sign outbound mails with the configured Selector.

dkim_sign_all_mail: <boolean> (default = 0)

DKIM sign all outgoing mails irrespective of the Envelope From domain.

Whitelist

All SMTP checks are disabled for those entries (e. g. Greylisting, SPF, RBL, …)

Note If you use a backup MX server (e.g. your ISP offers this service for you) you should always add those servers here.

Spam Detector Configuration

Options

Proxmox Mail Gateway uses a wide variety of local and network tests to identify spam signatures. This makes it harder for spammers to identify one aspect which they can craft their messages to work around the spam filter.

Every single e-mail will be analyzed and gets a spam score assigned. The system attempts to optimize the efficiency of the rules that are run in terms of minimizing the number of false positives and false negatives.

bounce_score: <integer> (0 - 1000) (default = 0)

Additional score for bounce mails.

clamav_heuristic_score: <integer> (0 - 1000) (default = 3)

Score for ClamAV heuristics (Encrypted Archives/Documents, Google Safe Browsing database, PhishingScanURLs, …).

languages: (all|([a-z][a-z])+( ([a-z][a-z])+)*) (default = all)

This option is used to specify which languages are considered OK for incoming mail.

maxspamsize: <integer> (64 - N) (default = 262144)

Maximum size of spam messages in bytes.

rbl_checks: <boolean> (default = 1)

Enable real time blacklists (RBL) checks.

use_awl: <boolean> (default = 1)

Use the Auto-Whitelist plugin.

use_bayes: <boolean> (default = 1)

Whether to use the naive-Bayesian-style classifier.

use_razor: <boolean> (default = 1)

Whether to use Razor2, if it is available.

wl_bounce_relays: <string>

Whitelist legitimate bounce relays.

Quarantine

Proxmox analyses all incoming e-mail messages and decides for each e-mail if its ham or spam (or virus). Good e-mails are delivered to the inbox and spam messages can be moved into the spam quarantine.

The system can be configured to send daily reports to inform users about the personal spam messages received the last day. That report is only sent if there are new messages in the quarantine.

Some options are only available in the config file /etc/pmg/pmg.conf, and not in the webinterface.

allowhrefs: <boolean> (default = 1)

Allow to view hyperlinks.

authmode: <ldap | ldapticket | ticket> (default = ticket)

Authentication mode to access the quarantine interface. Mode ticket allows login using tickets sent with the daily spam report. Mode ldap requires to login using an LDAP account. Finally, mode ldapticket allows both ways.

hostname: <string>

Quarantine Host. Useful if you run a Cluster and want users to connect to a specific host.

lifetime: <integer> (1 - N) (default = 7)

Quarantine life time (days)

mailfrom: <string>

Text for From header in daily spam report mails.

port: <integer> (1 - 65535) (default = 8006)

Quarantine Port. Useful if you have a reverse proxy or port forwarding for the webinterface. Only used for the generated Spam report.

protocol: <http | https> (default = https)

Quarantine Webinterface Protocol. Useful if you have a reverse proxy for the webinterface. Only used for the generated Spam report.

reportstyle: <custom | none | short | verbose> (default = verbose)

Spam report style.

viewimages: <boolean> (default = 1)

Allow to view images.

Customization of Rulescores

While the default scoring of SpamAssassin™'s ruleset provides very good detection rates, sometimes your particular environment can benefit from slightly adjusting the score of a particular rule. Two examples:

  • Your system receives spam mails which are scored at 4.9 and you have a rule which puts all mails above 5 in the quarantine. The one thing the spam mails have in common is that they all hit URIBL_BLACK. By increasing the score of this rule by 0.2 points the spam mails would all be quarantined instead of being sent to your users

  • Your system tags many legitimate mails from a partner organization as spam, because the organization has a policy that each mail has to start with Dear madam or sir (generating 1.9 points through the rule DEAR_SOMETHING). By setting the score of this rule to 0 you can disable it completely.

The system logs all rules which particular mail hits. Analyzing the logs can lead to finding such a pattern in your environment.

You can adjust the score of a rule by creating a new Custom Rule Score entry in the GUI.

Note In general it is strongly recommended to not make large changes to the default scores.

Virus Detector Configuration

Options

All mails are automatically passed to the included virus detector (ClamAV®). The default setting are considered safe, so it is usually not required to change them.

ClamAV® related settings are saved to subsection clamav in /etc/pmg/pmg.conf, using the following configuration keys:

archiveblockencrypted: <boolean> (default = 0)

Whether to mark encrypted archives and documents as heuristic virus match. A match does not necessarily result in an immediate block, it just raises the Spam Score by clamav_heuristic_score.

archivemaxfiles: <integer> (0 - N) (default = 1000)

Number of files to be scanned within an archive, a document, or any other kind of container. Warning: disabling this limit or setting it too high may result in severe damage to the system.

archivemaxrec: <integer> (1 - N) (default = 5)

Nested archives are scanned recursively, e.g. if a ZIP archive contains a TAR file, all files within it will also be scanned. This options specifies how deeply the process should be continued. Warning: setting this limit too high may result in severe damage to the system.

archivemaxsize: <integer> (1000000 - N) (default = 25000000)

Files larger than this limit (in bytes) won’t be scanned.

dbmirror: <string> (default = database.clamav.net)

ClamAV database mirror server.

maxcccount: <integer> (0 - N) (default = 0)

This option sets the lowest number of Credit Card or Social Security numbers found in a file to generate a detect.

maxscansize: <integer> (1000000 - N) (default = 100000000)

Sets the maximum amount of data (in bytes) to be scanned for each input file.

safebrowsing: <boolean> (default = 1)

Enables support for Google Safe Browsing.

Please note that the virus signature database it automatically updated. But you can see the database status on the GUI, and you can trigger manual updates there.

Quarantine

Indentified virus mails are automatically moved to the virus quarantine. The administartor can view those mails using the GUI, or deliver them in case of false positives. Proxmox Mail Gateway does not notify individual users about received virus mails.

Virus quarantine related settings are saved to subsection virusquar in /etc/pmg/pmg.conf, using the following configuration keys:

allowhrefs: <boolean> (default = 1)

Allow to view hyperlinks.

lifetime: <integer> (1 - N) (default = 7)

Quarantine life time (days)

viewimages: <boolean> (default = 1)

Allow to view images.

Custom SpamAssassin configuration

This is only for advanced users. SpamAssassin™'s rules and their associated scores get updated regularly and are trained on a huge corpus, which gets classified by experts. In most cases adding a rule for matching a particular keyword is the wrong approach, leading to many false positives. Usually bad detection rates are better addressed by properly setting up DNS than by adding a custom rule - watch out for matches to URIBL_BLOCKED in the logs or spam-headers - see the SpamAssassin DNSBL documentation.

To add or change the Proxmox SpamAssassin™ configuration please login to the console via SSH. Change to the /etc/mail/spamassassin/ directory. In this directory there are several files (init.pre, local.cf, …) - do not change them, as init.pre, v310.pre, v320.pre, local.cf will be overwritten by the template engine, while the others can get updated by any SpamAssassin™ package upgrade.

To add your special configuration, you have to create a new file and name it custom.cf (in this directory), then add your configuration there. Make sure to use the correct SpamAssassin™ syntax, and test with

# spamassassin -D --lint

If you run a cluster, the custom.cf file is synchronized from the master node to all cluster members automatically.

Should you only wish to adjust the score assigned to a particular rule you can also use the Custom Rule Score settings in the GUI.

Custom Check Interface

For use cases which are not handled by the Proxmox Mail Gateway Virus Detector and SpamAssassin™ configuration, advanced users can create a custom check executable which, if enabled will be called before the Virus Detector and before passing an e-mail through the Rule System. The custom check API is kept as simple as possible, while still providing a great deal of control over the treatment of an e-mail. Its input is passed via two CLI arguments:

  • the api-version (currently v1) - for potential future change of the invocation

  • the queue-file-name - a filename, which contains the complete e-mail as rfc822/eml file

The expected output need to be printed on STDOUT and consists of two lines:

  • the api-version (currently v1) - see above

  • one of the following 3 results:

    • OK - e-mail is ok

    • VIRUS: <virusdescription> - e-mail is treated as if it contained a virus (the virusdescription is logged and added to the e-mail’s headers)

    • SCORE: <number> - <number> is added (negative numbers are also possible) to the e-mail’s spamscore

The check is run with a 5 minute timeout - if it is exceeded the check executable is killed and the e-mail is treated as OK.

All output written to STDERR by the check is written with priority err to the journal/mail.log.

A simple sample script following the API (and yielding a random result) for reference:

#!/bin/sh

echo "called with $*" 1>&2

if [ "$#" -ne 2 ]; then
  echo "usage: $0 APIVERSION QUEUEFILENAME" 1>&2
  exit 1
fi

apiver="$1"
shift

if [ "$apiver" != "v1" ]; then
  echo "wrong APIVERSION: $apiver" 1>&2
  exit 2
fi

queue_file="$1"

echo "v1"

choice=$(shuf -i 0-3 -n1)

case "$choice" in
  0)
    echo OK
    ;;
  1)
    echo SCORE: 4
    ;;
  2)
    echo VIRUS: Random Virus
    ;;
  3) #timeout-test
    for i in $(seq 1 7); do
      echo "custom checking mail: $queue_file - minute $i" 1>&2
      sleep 60
    done
    ;;
esac

exit 0

The custom check needs to be enabled in the admin section of /etc/pmg/pmg.conf

section: admin
    custom_check 1

The location of the custom check executable can also be set there with the key custom_check_path and defaults to /usr/local/bin/pmg-custom-check.

User Management

User management in Proxmox Mail Gateway consists of three types of users/accounts:

Local Users

pmg-gui-local-user-config.png

Local users are used to manage and audit Proxmox Mail Gateway. Those users can login on the management web interface.

There are three roles:

  • Administrator

    Is allowed to manage settings of Proxmox Mail Gateway, except some tasks like network configuration and upgrading.

  • Quarantine manager

    Is allowed to manage quarantines, blacklists and whitelists, but not other settings. Has no right to view any other data.

  • Auditor

    With this role, the user is only allowed to view data and configuration, but not to edit it.

In addition there is always the root user, which is used to perform special system administrator tasks, such as updgrading a host or changing the network configuration.

Note Only pam users are able to login via the webconsole and ssh, which the users created with the web interface are not. Those users are created for Proxmox Mail Gateway administration only.

Local user related settings are saved in /etc/pmg/user.conf.

For details of the fields see user.conf

LDAP/Active Directory

pmg-gui-ldap-user-config.png

You can specify multiple LDAP/Active Directory profiles, so that you can create rules matching those users and groups.

Creating a profile requires (at least) the following:

  • profile name

  • protocol (LDAP or LDAPS; LDAPS is recommended)

  • at least one server

  • a user and password (if your server does not support anonymous binds)

All other fields should work with the defaults for most setups, but can be used to customize the queries.

The settings are saved to /etc/pmg/ldap.conf. Details for the options can be found here: ldap.conf

Bind user

It is highly recommended that the user which you use for connecting to the LDAP server only has the permission to query the server. For LDAP servers (for example OpenLDAP or FreeIPA), the username has to be of a format like uid=username,cn=users,cn=accounts,dc=domain , where the specific fields are depending on your setup. For Active Directory servers, the format should be like username@domain or domain\username.

Sync

Proxmox Mail Gateway synchronizes the relevant user and group info periodically, so that that information is available in a fast manner, even when the LDAP/AD server is temporarily not accessible.

After a successfull sync, the groups and users should be visible on the web interface. After that, you can create rules targeting LDAP users and groups.

Fetchmail

pmg-gui-fetchmail-config.png

Fetchmail is utility for polling and forwarding e-mails. You can define e-mail accounts, which will then be fetched and forwarded to the e-mail address you defined.

You have to add an entry for each account/target combination you want to fetch and forward. Those will then be regularly polled and forwarded, according to your configuration.

The API and web interface offer following configuration options:

enable: <boolean> (default = 0)

Flag to enable or disable polling.

interval: <integer> (1 - 2016)

Only check this site every <interval> poll cycles. A poll cycle is 5 minutes.

keep: <boolean> (default = 0)

Keep retrieved messages on the remote mailserver.

pass: <string>

The password used tfor server login.

port: <integer> (1 - 65535)

Port number.

protocol: <imap | pop3>

Specify the protocol to use when communicating with the remote mailserver

server: <string>

Server address (IP or DNS name).

ssl: <boolean> (default = 0)

Use SSL.

target: (?:[^\s\/\\@]+\@[^\s\/\\@]+)

The target email address (where to deliver fetched mails).

user: <string>

The user identification to be used when logging in to the server

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This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

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