164 lines
2.7 KiB
HTML
164 lines
2.7 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Blocking Access to Other SMTP Servers</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="Spam Filtering for Mail Exchangers"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Considerations"
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HREF="considerations.html"><LINK
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REL="PREVIOUS"
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TITLE="Multiple Incoming Mail Exchangers"
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HREF="multimx.html"><LINK
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REL="NEXT"
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TITLE="Forwarded Mail"
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HREF="forwardedmail.html"></HEAD
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><BODY
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CLASS="section"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Spam Filtering for Mail Exchangers: </TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="multimx.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 3. Considerations</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="forwardedmail.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="section"
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><H1
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CLASS="section"
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><A
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NAME="otherservers"
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></A
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>3.2. Blocking Access to Other SMTP Servers</H1
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><P
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> Any SMTP server that is not listed as a public <A
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HREF="gloss.html#mx"
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><I
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CLASS="glossterm"
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>Mail Exchanger</I
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></A
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> in the DNS zone of your domain(s) should not
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accept incoming connections from the internet. All incoming
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mail traffic should go through your incoming mail exchanger(s).
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</P
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><P
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> This consideration is not unique to SMTP servers. If you have
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machines that only serve an internal purpose within your site,
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use a firewall to restrict access to these.
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</P
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><P
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> This is a rule, so therefore there must be exceptions. However,
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if you don't know what they are, then the above applies to you.
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</P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="multimx.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="forwardedmail.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Multiple Incoming Mail Exchangers</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="considerations.html"
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ACCESSKEY="U"
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>Up</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>Forwarded Mail</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |