[DominikHoffmann]

I am wondering on what port email is coming into sendmail.

[ranga]

I am wondering on what port email is coming into sendmail.

Sendmail normally listens on port 25 (tcp) which is the well
known port number for smtp .

--ranga

[petej]

In the default Mac OS X configuration, sendmail isn't listening at all, which is a pretty good idea for new system administrators. If you choose to enable it, make sure you have some protection in place such as a firewall (which could be some ipfw controls, or use BrickHouse as a front-end to ipfw). Sendmail only needs to be listening if your machine is to act as a mail server; if you just want to receive mail from another server, you don't need sendmail to listen. Also if you want to send mail from one user on your system to another using the CLI "mail" command, you don't need sendmail to listen.

[petej]

Another thing...if you want to see the ports used by various protocols, you can run <BLOCKQUOTE><font size="1"face="Geneva, Verdana, Arial">code:</font><HR><pre><font size=1 face=courier>nidump services /</font>[/code]

<font face = "courier">man services</font> will explain the format of the file.

[ 02-25-2002: Message edited by: petej ]

[rkt]

Originally posted by petej:
<STRONG>Another thing...if you want to see the ports used by various protocols, you can run:
nidump services /</STRONG>

instead of messing around with nidump, there is a flat-file copy at /etc/services. however the apple supplied services file is a not very up to date. if you have nmap (http://www.insecure.org/nmap) installed it includes a more complete version in /usr/local/share/nmap/nmap-services.

[petej]

Instead of messing around with nmap (which is a terrific program, BTW), you can get the official up-to-date listing of port number assignments from the IANA page on port-numbers. The IANA is responsible for maintaining the port-number list.

(The original question was about what port sendmail listens on, so I'm just guessing that nmap is a little beyond where DominikHoffmann wanted to go today.)

[ 02-25-2002: Message edited by: petej ]

[DominikHoffmann]

(The original question was about what port sendmail listens on, so I'm just guessing that nmap is a little beyond where DominikHoffmann wanted to go today.)

Just a little.

Dominik Hoffmann

[rkt]

Originally posted by petej:
<STRONG>(The original question was about what port sendmail listens on, so I'm just guessing that nmap is a little beyond where DominikHoffmann wanted to go today.)</STRONG>

which is why i mentioned the nice, easy, honest-to-god test file at /etc/services... the rest was just a fyi.