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Old 07-31-2003, 05:46 PM   #1
sidkdbl07
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Question closing port 25 using sendmail


I am installing a webserver with Gentoo (LAMP). I'm now finished installing everything and all is working great.

Upon pointing nmap at this box I noticed that sendmail was listening on port 25. I only require sendmail to send stuff out so is there a way to get sendmail to not listen on port 25?

Any ideas welcome.
 
Old 07-31-2003, 11:44 PM   #2
DrOzz
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well if its not listening on port 25, then hows it going to send the mail, or is your actual question pertaining to changing it to a different port?
 
Old 08-01-2003, 01:00 AM   #3
ppuru
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as long as it is not listening on your external nic (the one connected to the Internet), no problems.

You can prevent that
1. by using iptables
2. /etc/mail/access (do not add the external IP address)
 
Old 08-01-2003, 10:32 AM   #4
sidkdbl07
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closing port 25

Adding the following line to sendmail.mc closed port 25 to an nmap scan

DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

Any problems with this?
 
Old 08-02-2003, 03:01 AM   #5
sashhoney
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u can use foll method to override the default smtp port setting.
In ur /etc/mail/sendmail.mc file add
DaemonOptions('port=999', Name='MTA')
and run m4 /etc/mail/sendmail.mc > /etc/sendmail.cf

For detailed explaination read
/usr/share/sendmail{version}/README
 
Old 08-02-2003, 04:46 AM   #6
ppuru
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Re: closing port 25

Quote:
Originally posted by sidkdbl07
Adding the following line to sendmail.mc closed port 25 to an nmap scan

DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

Any problems with this?
This will allow sendmail to accept mails from the localhost only, ignoring mails from your network. Users on your network cannot use this mail server to send mails ... if that is what you are looking at.
 
  


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