smtp port not turned on - how do i do it?

easy question for most of you, i'm sure:

for some reason, my smtp port is just not turned on. i can't receive incoming mail as a result. i don't know how to turn it on either. can someone shed the light?

i'm using rh 7.1.

thanks!

Is sendmail running on your system? Try running "/usr/sbin/sendmail" and then do "ps -ef |grep sendmail" you should see something like:

root 702 1 0 Jul19 ? 00:00:00 sendmail: accepting connections

Also, if you have "nmap" on your box run "nmap localhost" and look for the smtp entry. It should look like this:

25/tcp open smtp

And check /etc/services and ensure that smtp is present in the file and that its stanza is not commented out. Like this:

/etc #grep smtp /etc/services
smtp 25/tcp mail
smtp 25/udp mail
smtps 465/tcp # SMTP over SSL (TLS)

Hope this helps

yes, it was from nmap that i discovered that smtp port 25 isn't open even though sendmail is accepting connections (tried that also ) and the like.

all else looks good. /etc/services doesn't have anything commented out, but port 25 still is off.

what could it be?

Can you telnet to your smtp port successfully from the localhost? You might also kill your sendmail process and restart it using the command "/usr/bin/sendmail -bd -q this will run it in daemon mode (smtpd) and have it periodically process the queue. Once it's restarted try sending mail to an account on the localhost. If this fails you might try restarting network services and sendmail by running /etc/rc.d/init.d/network(or sendmail) restart. And again try sending mail to an account on the localhost.

also tried that. no matter what i do, smtp port 25 is not showing up as being open, and i can't figure out how to enable it....

I don't know of any more suggestions, but if you go to www.tek-tips.com there is a linux(server) and linux(client) forum which has a lot of extremely technically experienced people willing to help. Check them out and give www.linuxquestions.com a commecial there also.

hm. strange.

thanks for the help.

does anyone know if i need to add some configs to my ipchains file? i don't really know the syntax for ipchains configurations.

(still getting messages from other hosts - "can't send mail for the past four hours")

Do you have a firewall? Just a thought...

yeah, that was brought up by the network admin here. nope, i don't...

i actually tried running /usr/sbin/tcpd and it worked (it shows up on nmap at least, but i don't know if the mail is going through just yet).

is that normal?

scratch that. i have a tcp wrappers file that informs me when intruders break into the system, and well, it informed me that tcpd was a break-in attempt. so i'm not exactly sure how it just randomly turned on like that.

grr. forget that. smtp is not showing up as an open port anymore. and rebooting doesn't help.

btw, netstat -atu shows the following:

tcp 0 0 localhost.localdom:smtp *:* LISTEN

no outgoing smtp... only internal connections.

Ok forget everything you've been told.
It's a network issue not a security problem.

Your /etc/sendmail.cf file is setup so it only starts the service for localhost.

so do this to get it on your correct ip address interface.

first type:
# netstat -natp
will show you it's only on localhost accept
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 781/sendmail: accep

Then type this to stop the service:
#/etc/rc.d/init.d/sendmail stop

should say stopped.

now edit the sendmail.cf file in /etc

#vi /etc/sendmail.cf

change the line that says
# SMTP daemon options

O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA

to

# SMTP daemon options
O DaemonPortOptions=Port=smtp,Addr=your_external_ip_address, Name=MTA
# make the bit that says your_external_ip_address your linux servers external ip address.

Save and exit
now type
#/etc/rc.d/init.d/sendmail start

should say started!

now type:
# netstat -natp
should now be working on correct interface

tcp 0 0 32.96.111.130:25 0.0.0.0:* LISTEN 9288/sendmail: acce

Get this far and yours sorted.
Now you just have to make sure your ISP's DNS servers knows your email zone MX address for your SMTP server.

/Raz

wow raz, you are amazing. thanks

Red Hat changed the way that sendmail is run on version 7.1. They decided that most people need a client-only version of sendmail. So it is listening only on the localhost interface.