600 lines
9.1 KiB
HTML
600 lines
9.1 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>Limit queue processing to root</TITLE
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TITLE="Sendmail Administrative Tools"
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HREF="chap22sec185.html"></HEAD
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>Securing and Optimizing Linux: RedHat Edition -A Hands on Guide</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="chap22sec183.html"
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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 22. Software -Server/Mail Network</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="chap22sec185.html"
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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="AEN12660"
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>22.12. Limit queue processing to <TT
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CLASS="literal"
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>root</TT
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></A
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></H1
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><P
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> Ordinarily, anyone may process the queue with the -q switch. To limit queue processing to <TT
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CLASS="literal"
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>root</TT
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> and the owner of the queue directory, you must specify
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the <TT
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CLASS="envar"
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>restrictqrun</TT
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> option in the <TT
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CLASS="filename"
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>/etc/mail/sendmail.cf</TT
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> file.
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</P
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><P
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> Edit the <TT
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CLASS="filename"
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>sendmail.cf</TT
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> file, <B
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CLASS="command"
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>vi</B
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> <TT
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CLASS="filename"
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>/etc/mail/sendmail.cf</TT
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> and change the line:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="programlisting"
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> O PrivacyOptions=authwarnings,goaway,restrictmailq
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</PRE
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></TD
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></TR
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></TABLE
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>
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To read:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="programlisting"
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> O PrivacyOptions=authwarnings,goaway,restrictmailq,restrictqrun
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</PRE
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></TD
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></TR
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></TABLE
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>
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</P
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><P
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> Now re-start the sendmail process manually for the change to take effect:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# /etc/rc.d/init.d/sendmail <B
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CLASS="command"
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>restart</B
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>
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</PRE
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></TD
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></TR
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></TABLE
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>
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="literallayout"
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><TT
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CLASS="computeroutput"
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> Shutting down sendmail: [ OK ]
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Starting sendmail: [ OK ]
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</TT
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></PRE
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></TD
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></TR
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></TABLE
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>
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Any non-privileged user who attempts to process the queue will get this message:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [user@deep /]$ /usr/sbin/sendmail -q
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</PRE
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></TD
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></TR
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></TABLE
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>
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="literallayout"
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><TT
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CLASS="computeroutput"
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> You do not have permission to process the queue
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</TT
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></PRE
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></TD
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></TR
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></TABLE
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>
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</P
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><DIV
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CLASS="section"
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><H2
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CLASS="section"
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><A
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NAME="AEN12681"
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>22.12.1. The <SPAN
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CLASS="acronym"
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>SMTP</SPAN
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> greeting message</A
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></H2
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><P
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> When Sendmail accepts an incoming <SPAN
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CLASS="acronym"
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>SMTP</SPAN
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> connection it sends a greeting message to the other host. This message identifies the local machine and is the first thing it sends to say it is ready.
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</P
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><P
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> Edit the <TT
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CLASS="filename"
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>sendmail.cf</TT
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> file, <B
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CLASS="command"
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>vi</B
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> <TT
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CLASS="filename"
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>/etc/mail/sendmail.cf</TT
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> and change the line:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="programlisting"
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> O SmtpGreetingMessage=$j Sendmail $v/$Z; $b
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</PRE
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></TD
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></TR
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></TABLE
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>
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To read:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="programlisting"
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> O SmtpGreetingMessage=$j
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</PRE
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></TD
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></TR
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></TABLE
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>
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Now re-start the sendmail process manually for the change to take effect:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# /etc/rc.d/init.d/sendmail <B
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CLASS="command"
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>restart</B
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>
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</PRE
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></TD
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></TR
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></TABLE
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>
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="literallayout"
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> Shutting down sendmail: [ OK ]
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Starting sendmail: [ OK ]
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<TT
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CLASS="computeroutput"
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></TT
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></PRE
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></TD
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></TR
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></TABLE
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>
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</P
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><DIV
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CLASS="tip"
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><BLOCKQUOTE
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CLASS="tip"
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><P
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><B
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><SPAN
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CLASS="inlinemediaobject"
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><IMG
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SRC="./images/Tip.gif"
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ALT="Tip"
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></IMG
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></SPAN
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>: </B
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>
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This change doesn't actually affect anything, but was recommended by folks in the <TT
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CLASS="literal"
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>news.admin.net-abuse.email</TT
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> newsgroup as a legal precaution. It modifies the banner, which Sendmail displays upon receiving a connection.
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</P
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></BLOCKQUOTE
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></DIV
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><P
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> Do set the immutable bit on important Sendmail files, important Sendmail files can be set immutable for better security with the <B
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CLASS="command"
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>chattr</B
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> command of Linux. A file with the <TT
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CLASS="literal"
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>+i</TT
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> attribute
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cannot be modified, deleted or renamed. No link can be created to this file, and no data can be written to the file. Only the super-user can set or clear this attribute.
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</P
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><DIV
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CLASS="procedure"
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><OL
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TYPE="1"
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><LI
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><P
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> Set the immutable bit on the <TT
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CLASS="filename"
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>sendmail.cf</TT
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> file:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# <B
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CLASS="command"
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>chattr</B
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> +i /etc/mail/sendmail.cf
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</PRE
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></TD
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></TR
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></TABLE
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>
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</P
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></LI
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><LI
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><P
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> Set the immutable bit on the <TT
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CLASS="filename"
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>local-host-names</TT
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> file:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# <B
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CLASS="command"
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>chattr</B
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> +i /etc/mail/local-host-names
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</PRE
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></TD
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></TR
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></TABLE
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>
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</P
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></LI
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><LI
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><P
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> Set the immutable bit on the <TT
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CLASS="filename"
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>aliases</TT
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> file:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# <B
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CLASS="command"
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>chattr</B
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> +i /etc/mail/aliases
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</PRE
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></TD
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></TR
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></TABLE
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>
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</P
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></LI
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><LI
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><P
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> Set the immutable bit on the <TT
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CLASS="filename"
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>access</TT
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> file:
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="screen"
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> [root@deep] /# <B
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CLASS="command"
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>chattr</B
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> +i /etc/mail/access
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</PRE
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></TD
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></TR
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></TABLE
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>
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</P
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></LI
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></OL
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></DIV
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><P
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> Further documentation and for more details, there are several man pages you can read:
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<P
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></P
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><DIV
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CLASS="variablelist"
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><DL
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>aliases</SPAN
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>(5)</SPAN
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></DT
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><DD
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><P
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> - aliases file for sendmail
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</P
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></DD
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>makemap</SPAN
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>(8)</SPAN
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></DT
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><DD
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><P
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> - create database maps for sendmail
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</P
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></DD
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>sendmail</SPAN
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>(8)</SPAN
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></DT
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><DD
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><P
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> - an electronic mail transport agent
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</P
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></DD
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>mailq</SPAN
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>(1)</SPAN
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></DT
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><DD
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><P
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> - print the mail queue
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</P
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></DD
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>newaliases</SPAN
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>(1)</SPAN
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></DT
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><DD
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><P
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> - rebuild the data base for the mail aliases file
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</P
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></DD
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>mailstats</SPAN
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>(8)</SPAN
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></DT
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><DD
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><P
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> - display mail statistics
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</P
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></DD
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><DT
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><SPAN
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CLASS="citerefentry"
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><SPAN
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CLASS="refentrytitle"
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>praliases</SPAN
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>(8)</SPAN
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></DT
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><DD
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><P
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> - display system mail aliases
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</P
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></DD
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></DL
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></DIV
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>
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</P
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></DIV
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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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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
|
|
HREF="chap22sec183.html"
|
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>Prev</A
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></TD
|
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><TD
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WIDTH="34%"
|
|
ALIGN="center"
|
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VALIGN="top"
|
|
><A
|
|
HREF="index.html"
|
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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="chap22sec185.html"
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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%"
|
|
ALIGN="left"
|
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VALIGN="top"
|
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>The <TT
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CLASS="filename"
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>/etc/mail/aliases</TT
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> file</TD
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><TD
|
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WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
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><A
|
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HREF="soser-mailn.html"
|
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>Up</A
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></TD
|
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><TD
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WIDTH="33%"
|
|
ALIGN="right"
|
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VALIGN="top"
|
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>Sendmail Administrative Tools</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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> |