Chapter 20 Content Filtering – Mail Filters - Planet Networking & Communication MH-5001 User Manual

MH-5001 User Manual
20.1 Demands
1. Sometimes there are malicious scripts like *.vbs that may be attached in the email. If the users accidentally open such files,
their computers may be infectious with virus.
2. You may receive some commercial mails which always persecute you and waste your time to deal with.
20.2 Objectives
1. Modify the filename extension of the suspicious email attachments so that email receivers may notice that the file cannot
be directly opened by the operating system because of the unrecognized filename extension.
2. Restrict the commercial mails to send or to be received and append "[SPAM]" to email subject if recognized as SPAM
email so that email receivers may easily judge what he should do next step while receiving such mails.
20.3 Methods
1. Setup SMTP filters for outgoing emails from PC_1 (in LAN1) towards the mail server (in DMZ1 or in WAN1) to block the
suspicious attachments like vbs, exe, etc. extension files.
2. Setup POP3 filters for incoming emails from a mail server (in WAN1 or in DMZ1) to PC_1 (in LAN1) to append a ".bin"
to all suspicious attachments like vbs, exe, etc. extension files.
3. Setup IMAP filters for incoming emails from a mail server (in WAN1 or in DMZ1) to PC_1 (in LAN1) to append a ".bin"
to all suspicious attachments like vbs, exe, etc. extension files.
4. Setup SMTP filters for outgoing emails from PC_1 (in LAN1) towards the mail server (in DMZ1 or in WAN1) to block the
mails by the black list and let the trusted mails passing through and append "[SPAM]" to email subject if recognized as
SPAM emails.
5. Setup POP3 filters for incoming emails from a mail server (in WAN1 or in DMZ1) to PC_1 (in LAN1) to block the mails
by the black list and let the trusted mails passing through and append "[SPAM]" to email subject if recognized as SPAM
email.
6. Setup IMAP filters for incoming emails from a mail server (in WAN1 or in DMZ1) to PC_1 (in LAN1) to block the mails
by the black list and let the trusted mails passing through and append "[SPAM]" to email subject if recognized as SPAM
email.
Content Filtering – Mail Filters
This chapter introduces SMTP proxies and explains how to implement it.
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Chapter 20
Content Filtering – Mail Filters
Chapter 20