The Pop3 Alg - D-Link DFL-1660 User Manual

6.2.6. The POP3 ALG

asdf.egrhb.net
To examine the statistics for a particular DNSBL server, the following command can be used.
gw-world:/> dnsbl smtp_test zen.spamhaus.org -show
BlackList: zen.spamhaus.org
Status
Weight value : 25
Number of mails checked
Number of matches in list
Number of failed checks (times disabled)
To clean out the dnsbl cache for my_smtp_alg and to reset all its statistical counters, the following
command option can be used:
gw-world:/> dnsbl my_smtp_alg -clean
6.2.6. The POP3 ALG
POP3 is a mail transfer protocol that differs from SMTP in that the transfer of mail is directly from a
server to a user's client software.
POP3 ALG Options
Key features of the POP3 ALG are:
Block clients from sending USER
and PASS command
Hide User
Allow Unknown Commands
Fail Mode
Verify MIME type
Block/Allow filetype
: active
Tip: DNSBL servers
A list of DNSBL servers can be found at:
http://en.wikipedia.org/wiki/Comparison_of_DNS_blacklists.
active 5
Block connections between client and server that send the
username/password combination as clear text which can be
easily read (some servers may not support other methods than
this).
This option prevents the POP3 server from revealing that a
username does not exist. This prevents users from trying
different usernames until they find a valid one.
Non-standard POP3 commands not recognized by the ALG
can be allowed or disallowed.
When content scanning find bad file integrity then the file can
be allowed or disallowed.
The content of an attached file can be checked to see if it
agrees with its stated filetype. A list of all filetypes that are
verified in this way can be found in Appendix C, Verified
MIME filetypes. This same option is also available in the
HTTP ALG and a fuller description of how it works can be
found in Section 6.2.2, "The HTTP ALG".
Filetypes from a predefined list can optionally be blocked or
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Chapter 6. Security Mechanisms
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