POP3

This page contains configuration options for the spamassassin mail filter and how it should manage the e-mails recognised as spam.

Global settings

On this page, by ticking the appropriate checkboxes, a few global configuration settings of the POP3 proxy can be enabled.

Enabled on Green, Enabled on Blue, Enabled on Orange

Enable the POP3 e-mail scanner on the GREEN, BLUE, and ORANGE zone, respectively. They appear only if the corresponding zones are enabled.

Virus scanner

Activate the virus scanner.

Spam filter

Enable spam filtering on the e-mails.

Intercept SSL/TLS encrypted connections

When the checkbox is ticked, also connections over SSL/TLS are scanned for virus.

New in version 3.0.

Firewall logs outgoing connections

Let all the outgoing connections be logged by the firewall.

Spam filter

This page allows to configure how the POP3 proxy should proceed when it finds a spam e-mail.

Note

Even when an email has been marked as spam, it will be delivered to the original recipient. Indeed, not delivering it would break RFC 2821, which states that once an email is accepted, it must be delivered to the recipient.

Spam subject tag

The prefix that will be added to the subject of the e-mail recognised as spam.

Add spam report to mail body

Tick the checkbox to replace, in each spam e-mail, the body of the original e-mail with a report of the spamassassin daemon with the summary of its findings, i.e. with the reasons why the e-mail has been reported as spam.

Required hits

The number of hits required for a message to be considered as spam.

Activate support for Japanese emails

Tick this checkbox to activates support for Japanese character sets in e-mails to search for Japanese spam.

Enable message digest spam detection (pyzor)

To detect spam e-mails using pyzor (in short: spam e-mails are converted to a unique digest message that can be used to identify further analogous spam e-mails).

Warning

Activating this option might considerably slow down the POP3 proxy!

White list

A list of e-mail addresses or whole domains, specified using wildcards, e.g., *@example.com, one address per line. E-mails sent from these addresses and domains will never be checked for spam.

Black list

A list of e-mail addresses or whole domains, specified using wildcards, e.g., *@example.com, one address per line. E-mails sent from these addresses and domains will always be marked as spam.

The settings can be saved by clicking on the Save Button.

Encrypted e-mails.

The Endian UTM Appliance is unable to scan the e-mails sent through a POP3 SSL connection since it is an encrypted channel.

Therefore, to allow a client to use POP3 over SSL it is necessary to appropriately configuring it and to disable the encryption from the client to the Endian UTM Appliance. Encryption should be disabled (i.e., do not use SSL), but the port for POP3 traffic in plain text changed from the default 110 to 995.

After setting this configuration, the connection from the client to the Endian UTM Appliance will remain in plain text, but it will use port 995, making the Endian UTM Appliance setup an encrypted POP3 over SSL connection from it to the POP3 server.