Hi Richard, On Sat, May 7, 2011 at 1:50 PM, lists-redhat < replies-lists-b3z1-redhat@xxxxxxxxxxxxxxxxxxxxx> wrote: > if you're telnetting specifically to port 25, the smtp port (not > generically to the machine, which will get you to port 23) and > you're getting "connection lost" or "connection timed out", then you > most likely have some type of a firewall issue. > Yes, for the experiment I was telnetting specifically to port 25. Your assessment of the issue does appear to have merit: Note that when I sent an email from my gmail account to my workstation, gmail eventually sent me a warning stating that "The recipient server did not accept our requests to connect." Which seems to reinforce your theory. > from the machine itself, try telnetting to its port 25 *by ipnumber* > (not name). make certain that you see that it's not trying to > connect to 127.0.0.1 (which will probably happen if you try by > name). if you get a connect, then it's likely an off-host > firewall/routing issue. > I got a connection to sendmail. > > then, try telnetting to "127.0.0.1 25" -- you should get sendmail > connect. > I got a connection to sendmail. > if the telnetting to port 25 by the machine's ipnumber gets a hang > then you likely have an on-host firewall issue. iptables is the most > likely machine-specific firewall. you can look in /etc/sysconfig to > see if you have an iptables setup. if so, turn iptables off and try > telnetting in to port 25 (by ipnumber and from off-host) and see > what you get. > > if the issue appears to be an off-host firewall issue, then you need > to step back and see what's going on from the outside. > It would seem that I am here, right? > > [honestly, if you did nothing to your machine setup, i'd bet on some > external/network change to be causing your issue.] > I'm a little nervous that the updates that were installed did something to cause this side affect--but by reading their descriptions, that shouldn't of been the case. Furthermore, since I downgraded the respective patches I should be back to a working system. Thus, I am in agreement that it _does_ seem to be something external to my machine. Although, my IT dept does not agree; so I may be out of luck. > > [by the way, you don't need to reboot the machine to restart > sendmail, or other service starts/stops (rebooting to restart/fix > things is the windows approach to life, and not generally necessary, > or recommended, in the unix world.)] > Agreed. I did the reboots in response to downgrading packages. Strictly speaking, the downgrades did not require reboots. But because the downgrade had no affect on my problem, I thought I'd reboot--just in case. Plus, I was desperate. Kind regards, -- Mun > > - Richard > > > ------------ Original Message ------------ > > Date: Saturday, May 07, 2011 01:09:55 PM -0700 > > From: Mun <mjelists@xxxxxxxxx> > > To: redhat-list@xxxxxxxxxx > > Subject: Re: Help Needed: My RHEL5 box suddenly stopped accepting > e-mails > > > > Hi Richard, > > > > > > On Sat, May 7, 2011 at 3:38 AM, lists-redhat < > > replies-lists-b3z1-redhat@xxxxxxxxxxxxxxxxxxxxx> wrote: > > > >> in your .cf, what do you have as an active (not commented out) > >> option the under: > >> > >> # SMTP daemon options > >> > >> tag? > >> > >> is it: > >> > >> O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA > >> > >> or something more along the lines of one of the following: > >> > >> O DaemonPortOptions=Name=IPv4, Family=inet > >> > >> O DaemonPortOptions=Name=MTA > >> > > > > I have the choice immediately above in my sendmail.cf: > > DaemonPortOptions=Name=MTA > > > > > >> > >> The first, with the 127.0.0.1, is the default for RHEL and will > >> only accept localhost mail. The other two are forms will allow it > >> to accept mail from off localhost. > >> > >> If that looks ok, try telnetting to port 25 on this machine from > >> off-host - e.g., from the exchange server. Do you get a > >> "connection refused" response or a "hang". If "connection > >> refused", then it's most likely the sendmail daemon doing the > >> blocking. If you get a "hang", then it's likely a firewall of > >> some nature, e.g., iptables. > >> > > > > I get "connection lost" or "Connection timed out"; depending on > > the computer I use to run telnet. > > The "connection lost" is what my Windows XP box returned; and the > > "Connection timed out" is what > > another Linux box returned. > > > > > >> Have you looked at your machine's logs (maillog, messages, secure > >> being the most obvious) they may give some hints. > >> > > > > Yes. I have looked at those, as has the company's IT dept. But > > there were no messages that > > would help with this issue. > > > > > >> > >> Have you restarted sendmail? > >> > > > > Yes. I've also rebooted a coupled of times; nothing seems to help. > > > > It's just so weird that with no obvious changes made (except for > > the updates applied and then > > downgraded that I mentioned in my initial message) that my box > > would just all of the sudden > > stop accepting email. > > > > Thanks very much for the reply. I greatly appreciate the ideas. > > > > Regards, > > > > -- > > Mun > > > > > > > >> > >> - Richard > >> > >> > >> > >> ------------ Original Message ------------ > >> > Date: Friday, May 06, 2011 04:48:34 PM -0700 > >> > From: Mun.Johl@xxxxxxxxxx > >> > Subject: RE: Help Needed: My RHEL5 box suddenly stopped > >> > accepting > >> e-mails > >> > > >> > Hi Richard, > >> > > >> > Thanks for your reply. > >> > > >> > I had saved off /etc/mail when we first got email working > >> > properly on my system (a couple of years ago) and I compared > >> > the current sendmail.cf to the "known good" copy. The only > >> > difference I see is that IT has uncommented the following line: > >> > > >> > O Timeout.ident=0 > >> > > >> > With respect to sendmail.mc, the version currently used by the > >> > system had the following lines commented out: > >> > > >> > MASQUERADE_AS(`mydomain.com')dnl > >> > FEATURE(masquerade_envelope)dnl > >> > MASQUERADE_DOMAIN(localhost)dnl > >> > MASQUERADE_DOMAIN(localhost.localdomain)dnl > >> > > >> > I'm not too experienced with sendmail, but it doesn't appear to > >> > me as if the changes above would result in the problem I am > >> > having; does it? > >> > > >> > Regards, > >> > >> ------------ End Original Message ------------ > >> > >> > > ------------ End Original Message ------------ > > > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
