Hi Barry, Thanks for replying. Some of the points were previously brought up by others; but I'll try to address your points the best I can. On Sat, May 7, 2011 at 11:37 PM, Barry Brimer <lists@xxxxxxxxxx> wrote: > I've not been following this too closely, but I'll make a few suggestions > in no particular order. > > 1. Add an iptables logging rule that logs and connections to port 25 not > from localhost. Something like: > iptables -I INPUT -i ! lo -p tcp -m tcp --dport 25 -j LOG > I am going to wait on the change because I don't feel comfortable doing this just yet. Note that we have established that systems on my subnet can successfully telnet into port 25 of my system; whereas systems on other subnets cannot. Would the logging rule above provide additional information regarding the failed connection attempts to port 25? > > Verify connections (or lack thereof) in /var/log/messages > > 2. Is SELinux enabled? Find out with "getenforce" .. if it is on, turn it > off temporarily with "setenforce 0" (as root) > SELinux is Disabled. > > 3. Is there anything relevant in /var/log/messages /var/log/maillog > /var/log/audit/audit.log ?? > None that I or my IT dept could find. > > 4. Make sure you're not out of inodes with "df -i" > Plenty of inodes. > > 5. Try connecting to the mail server manually from another machine on the > same subnet. > I can do that successfully. > > 6. Verify other Internet communications work .. perhaps you've got a bad > route of some kind. > I seem to be able to do other internet activity without any problems. > > 7. Run some tests with swaks <http://jetmore.org/john/code/swaks/> > I'm not familiar with swaks; but I'll look into it. > > 8. Use system-switch-mail to verify that your system is using sendmail. > My system is running sendmail. However, I'm not familiar with system-switch-mail, nor could I find that command on my system. > 9. Add a second local IP address to your machine .. test that as well, see > if there are any different results. > That's a good idea, but not easily executed because I would need IT to help me out. > > Good luck. > Thanks! And thank you for replying. Regards, -- Mun > > Barry > > On Sat, 7 May 2011, Mun wrote: > > Hi Bohdan, >> >> >> On Sat, May 7, 2011 at 10:21 PM, Bohdan Sydor <bohdan@xxxxxxxxxx> wrote: >> >> On 05/08/2011 06:30 AM, Mun wrote: >>> >>> Does everything above look okay? >>>> >>> >>> Yes, they all seem to be alright. >>> >>> Next, let's try to telnet to the smtp port: >>> >>> - from the localhost. Simply telnet localhost 25 and try to submit a >>> sample msg. >>> >>> >> You are now beyond my understanding of sendmail. After telnetting, >> what is the command I should enter? >> >> >> - from any other machine that is in the same subnet as the mail server >>> >>> >>> From any other remote hosts we already know that it fails. But do you >>>> >>> refer to the MTA by address or by name? Check the DNS entries for the >>> MTA: >>> >>> host -t mx yourDomainName >>> >>> >> This returned a name (not an address). Let say "xyz1.domain" >> >> >> >> host -t a theResultNameFromPreviousCmd >>> Is it the same IP as assigned to the server? >>> >>> >> Yes, the IP does match that of "xyz1.domain" >> >> But this piqued my interest, and when I look in sendmail.cf I see the >> following lines: >> # "Smart" relay host (may be null) >> DSabc1.domain >> >> Should this entry be "xyz1.domain" (to match the the 'host -t mx' >> command's >> output)? >> Or is it okay that the line in sendmail.cf refers to a different server? >> >> Best regards, >> >> -- >> Mun >> >> >> >> >> >>> -- >>> regards >>> >>> Bohdan Sydor >>> www.sydor.net >>> >>> -- >>> redhat-list mailing list >>> unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe >>> https://www.redhat.com/mailman/listinfo/redhat-list >>> >>> -- >> redhat-list mailing list >> unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe >> https://www.redhat.com/mailman/listinfo/redhat-list >> >> !DSPAM:4dc6368f135391813713156! >> >> >> > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
