Features
--------
+[[intro_spam_detection]]
Spam detection
~~~~~~~~~~~~~~
SMTP Whitelist::
Exclude senders from SMTP blocking. To prevent all SMTP checks
-(Greylisting, Receiver Verification, SPF and RBL) and accept all
+(Greylisting, Receiver Verification, SPF and DNSBL) 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
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 an email means that unknown senders are intentionally temporarily
+rejected. Since temporary failures are part of the specifications for mail
+delivery, a legitimate server will try to resend the email later on. Spammers
+on the other hand, do not queue and reattempt mail delivery. A greylisted email
+never reaches your mail server and thus your mail server will not send useless
+"Non Delivery Reports" to spammers. Additionally greylisted mail is not
+analyzed by the antivirus and spam-detector engines, which saves resources.
+
-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.
+A mail is greylisted if it is the first mail from a sender to a receiver
+coming from a particular IP network. You can configure which IP addresses
+belong to the same network, by setting an appropriate netmask for greylisting.
SMTP Protocol Tests::
`man postscreen`). Most spam is sent out by zombies (malware on
compromised end-user computers), and those zombies often try to
maximize the amount of mails delivered. In order to do that, many of
-them violates the SMTP protocol specification and can thus be detected
+them violate the SMTP protocol specification and thus can get detected
by these tests.
+Before and After Queue Filtering::
+
+{pmg} can be configured to either accept the mail, by sending a response
+of '250 OK', and scan it afterwards, or alternatively inspect the mail
+directly after it has the content and respond with a reject '554' if the
+mail is blocked by the rule system. These options are known as After Queue
+and Before Queue filtering respectively (see
+xref:pmgconfig_mailproxy_before_after_queue[Before and After Queue Scanning]).
+
+Configurable NDR policy::
+
+In certain environments it can be unacceptable to discard an email, without
+informing the sender about that decision. You can decide whether you want
+to inform the senders of blocked emails or not.
Virus detection
~~~~~~~~~~~~~~~
sophisticated, highly customized configurations blocking certain types
of e-mails and generating notifications.
+Web-based Management Interface
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+{pmg} makes email security and filtering simple to manage. A web-based
+management interface allows you to setup and maintain even a complex mail
+setup with ease.
+
+[thumbnail="pmg-gui-dashboard.png"]
+
+There is no need to install a separate management tool. Every modern internet
+browser is sufficient.
Spam Quarantine
~~~~~~~~~~~~~~~
-Identified Spam mails can be stored to the user accessible Spam
-quarantine. Thus users can view and manage there Spam mails by
-themselves.
+Identified Spam mails can be stored to the user-accessible Spam quarantine.
+Users can so view and manage their Spam mails by themselves.
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 control all
+all available logs. With the web-based and user-friendly management
+interface, IT admins can easily overview and control all
functions from a single screen.
The Message Tracking Center is very fast and powerful, tested on {pmg}
files from the last 7 days can be queried and the results are
summarized by an intelligent algorithm.
+The logged information includes:
+
- Arrival of the email
- Proxmox filtering processing with results
- Internal queue to your email server
- Status of final delivery
+DKIM Signing
+~~~~~~~~~~~~
+
+{pmg} offers the possibility to optionally sign outgoing emails with
+xref:pmgconfig_mailproxy_dkim[DKIM].
+
+
High Availability with Proxmox HA Cluster
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
LDAP integration
~~~~~~~~~~~~~~~~
-It is possible to query user and group data from LDAP servers. This
-may be used to build special filter rules, or just to provide
-authentication services for the Spam quarantine GUI.
+It is possible to query user and group data from LDAP servers. This may be
+used to build special filter rules, or just to provide authentication services
+for the Spam quarantine GUI.
Fetchmail integration
Flexible User Management
~~~~~~~~~~~~~~~~~~~~~~~~
-The administration interface uses a role based access control scheme,
+The administration interface uses a role-based access control scheme,
using the following roles:
Superuser::
Has read-only access to the whole configuration, can access logs and
view statistics.
+Helpdesk::
+
+Combines permissions of the 'Auditor' and the 'Quarantine Manager' role.
+
Your benefit with {pmg}
-----------------------
projects / pmg-docs.git / blobdiff