Introduction ============ What is {pmg}? -------------- E-mail security begins at the gateway by controlling all incoming and outgoing e-mail messages. {pmg} addresses the full spectrum of unwanted e-mail traffic, focusing spam and virus detection. {pmg} provides a powerful and affordable server solution to eliminate spam, viruses and blocking undesirable content from your e-mail system. All products are self-installing and can be used without deep knowledge of Linux. image::images/Proxmox-Mailprocessing.png[] Features -------- Spam detection ~~~~~~~~~~~~~~ {pmg} uses a wide variety of local and network tests to identify spam mail. Here is a short list of used filtering methods: Receiver Verification:: Many of the junk messages reaching your network are emails to non-existent useres. Proxmox Mail Gateway detects these emails on SMTP level, which means before they are transferred to your networks. This reduces the traffic to be analyzed for spam and viruses up to 90% and reduces the working load on your mail servers and scanners. Sender policy framework (SPF):: Sender Policy Framework (SPF) is an open standard for validating emails and to prevent sender IP address forgery. SPF allows the administrator of an Internet domain to specify which computers are authorized to send emails with a given domain by creating a specific SPF record in the Domain Name System (DNS). DNS-based Blackhole List:: A DNS-based Blackhole List (DNSBL) is a means by which an Internet site may publish a list of IP addresses, in a format which can be easily queried by computer programs on the internet. The technology is built on top of the Domain Name System. DNSBLs are used to publish lists of addresses linked to spamming. SMTP Whitelist:: Exclude senders from SMTP blocking. To prevent all SMTP checks (Greylisting, Receiver Verification, SPF and RBL) and accept all e-mails for the analysis in the filter rule system, you can add the following to this list: Domains (Sender/Receiver), Mail address (Sender/Receiver), Regular Expression (Sender/Receiver), IP address (Sender), IP network (Sender) Bayesian Filter - Automatically trained statistical filters:: Some particular words have a higher probability of occurring in spam emails rather than in legitimate emails. By beeing trained to recognize those words, the Bayesian checks every email and adjusts the probabilities of it beeing a spam word or not in its database. This is done automatically. Black- and Whitelists:: Black- and Whitelists are an access control mechanism to accept, block, or quarantine emails to recipients. This allows you to tune the rule-system by applying different objects like domains, email address, regular expression, IP Network, LDAP Group, and others. Autolearning algorithm:: Proxmox Mail Gateway gathers statistical information about spam emails. This information is used by an autolearning algorithm, so the system becomes smarter over time. Spam Uri Realtime BlockList (SURBL):: SURBLs are used to detect spam based on message body URIs (usually web sites). This makes them different from most other Real-time Blocklists, because SURBLs are not used to block spam senders. SURBLs allow you to block messages that have spam hosts which are mentioned in message bodies. Greylisting:: Greylisting an email from a sender your system does not recognize, means, that it will be temporarily rejected. Since temporary failures are built into the RFC specifications for mail delivery, a legitimate server will try to resend the email later on. This is an effective method because spammers do not queue and reattempt mail delivery as is normal for a regular Mail Transport Agent. + Greylisting can reduce e-mail traffic up to 50%. A greylisted email never reaches your mail server and thus your mail server will not send useless "Non Delivery Reports" to spammers. Virus detection ~~~~~~~~~~~~~~~ {pmg} integrates {clamav}, which is an open-source (GPL) antivirus engine designed for detecting trojans, viruses, malware and other malicious threats. It provides a high performance mutli-threaded scanning daemon, command line utilities for on demand file scanning, and an intelligent tool for automatic signature updates. Object-Oriented Rule System ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The object-oriented rule system enables custom rules for your domains. It’s an easy but very powerful way to define filter rules by user, domains, time frame, content type and resulting action. {pmg} offers a lot of powerful objects to configure your own custom system. ACTIONS - objects:: Defines the final actions. WHO - objects:: Who is the sender or receiver of the e-mail? WHAT - objects:: What is in the e-mail? WHEN - objects:: When is the e-mail received by Proxmox Mail Gateway? Every rule has five categories FROM, TO, WHEN, WHAT and ACTION. Every of these categories can contain several objects and a direction (in, out or both). Options range from simple spam and virus filter setups to sophisticated, highly customized configurations blocking certain types of e-mails and generating notifications. Tracking and Logging ~~~~~~~~~~~~~~~~~~~~ The innovative Proxmox Message Tracking Center tracks and summarizes all available logs. With the web-based and user friendly management interface, the IT admins can easily overview and controll all functions from a single screen. The Message Tracking Center is very fast and powerful, tested on {pmg} sites processing over a million emails per day. All different log files from the last 7 days can be queried and the results are summarized by an intelligent algorithm. - Arrival of the email - Proxmox filtering processing with results - Internal queue to your email server - Status of final delivery High Availability with Proxmox HA Cluster ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ To provide a 100% secure email system for your business, we developed Proxmox High Availability (HA) Cluster. The Proxmox HA Cluster uses a unique application level clustering scheme, which provides extremely good performance. Fast set-up within minutes and a simple, intuitive management keep resource needs low. After temporary failures, nodes automatically reintegrate without any operator interaction. Your benefit with {pmg} ----------------------- * Open source software * No vendor lock-in * Linux kernel * Fast installation and easy-to-use * Web-based management interface * REST API * Huge active community * Low administration costs and simple deployment include::getting-help.adoc[]