Linux - NewbieThis Linux forum is for members that are new to Linux.
Just starting out and have a question?
If it is not in the man pages or the how-to's this is the place!
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Introduction to Linux - A Hands on Guide
This guide was created as an overview of the Linux Operating System, geared toward new users as an exploration tour and getting started guide, with exercises at the end of each chapter.
For more advanced trainees it can be a desktop reference, and a collection of the base knowledge needed to proceed with system and network administration. This book contains many real life examples derived from the author's experience as a Linux system and network administrator, trainer and consultant. They hope these examples will help you to get a better understanding of the Linux system and that you feel encouraged to try out things on your own.
Click Here to receive this Complete Guide absolutely free.
I am new to this forum. However, I have a question that I have been trying to solve for several days now. I tried to search for the answer on google, but no matter where I go, I find different suggestions and nothing has seemed to work yet. I am a bit confused on this....
The question is dealing with sendmail. We use webmin and the command prompt to work on our Linux server (Red Hat Linux). Everything seems to be set up correctly. However, for some reason, our application through which we send mail from (using php), does not want to send out email to EXTERNAL addresses. I have no problem sending out email to internal addresses (meaning within our campus). However, if I try to send out an email to someone with an address at comcast or hotmail, the email gets stuck in the mail queue, with the error message: "deferred...no route to host." Is this an issue with relaying? Or perhaps I have sendmail.mc configured incorrectly? Could you please give me some suggestions of what can be done to fix this problem! This would be really appreciated!
Actually, I can ping addresses outside my computer. I am able to access the internet overall. -I do have an IP address. Or do you mean pinging through sendmail? (How would I try this?) (I know that I can go to Start > Run > cmd > and ping an external address, like yahoo.com. This works by the way.)
Inside the sendmail.mc file, i have this option set: ('Smart_Host','mail.my.provider'). In other words, the relay server is listed: mail.my.provider. Could this be a problem with relaying?
Also, I have this option set: dn1 DAEMON_OPTIONS('Port=smtp, Addr = 127.0.0.1, Name=MTA')
-I thought perhaps this was where the problem was, since the IP address is only specified from 127.0.0.1 (our campus). However, when I changed this option to equal 0.0.0.0, the problem still exists. The mail, although I flushed it after this, still is in the outbox. (I compiled sendmail.cf and restarted sendmail after making the changes of course.)
First I thought perhaps the addresses have something wrong with them. However, I even tried a test email and tried to send out an email to one of MY external addresses. Sure enough, this email got stuck also in the outbox.
Correction: I meant I can ping addresses outside the CAMPUS (wrote computer). I thought this may have been a routing issue... but when I contacted the ITS center for our campus, everything seems to be fine. It seems that this is only a Sendmail issue. Perhaps it is not configured properly... I started using sendmail quite recently and therefore, am very new to it. As a result, I am not sure what is causing this problem. Perhaps someone has experienced this problem before, with Sendmail?
Thanks for the reply. I actually did not copy & paste the line(s). -I probably should have done that! But thanks for the corrections. I looked at sendmail.mc and it looks like I have this setup correctly:
(copied & pasted):
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')
~This line, however, does not have the dnl at the end. (I just noticed this.) So I will try this!
As far as sending email, the email is sent out from different addresses, through our ticketing system. Here is an example of a message that I have "stuck" in the outbox:
Tue, 3 Aug 2004 09:35:37 -0400 email@example.com firstname.lastname@example.org 1 kB Deferred: mailin-04.mx.aol.com.: No route to host
I will change the above line & will let you guys know if this works!
Hey guys! Thanks for all your help! I finally got this issue resolved! Pete, the distribution that I am using is Red Hat. However, when I checked the setup at /etc/mail/local-host-names, everything seems to be setup correctly there. Also, when I typed the command 'hostname,' it looks like I do have a FQDN.
But I finally got the mail to send out to external addresses by playing with the options for Sendmail via Webmin. :-) (Webmin makes it a lot easier to configure Sendmail.) All I did was go into "Sendmail Options" and changed the first option "Send outgoing mail via host" FROM deliver directly,TO the name of our ISPs SMTP server. And sure enough, all stuck messages (and there were a lot) successfully sent out! I have sent some test emails and everything seems to be working now. So I guess this was basically a routing problem? For some reason the mail did not want to send via the host DIRECTLY and forwarding it via our ISPs SMTP server got it to work! I will continue to monitor this though.
Sorry for the delayed reply. To answer your question, the messages that failed to send out via sendmail reside at the following path: /var/spool/mqueue
I believe that all users that have sendmail setup and configured, the mail queue always resides in this location. If there are messages there, then they have not been sent out yet. I checked the dates on mine and realized that mail to external addresses was not sending out for about 2-3 days. Therefore, I archived and zipped the messages and saved them in a different location. When I finally got the issue resolved, I placed these messages back into the mail queue and they were then successfully sent out (after restarting sendmail).
You are correct, the only thing that I changed was a "sendmail option." However, I did this via webmin. (Using webmin, there is a way to see if there are messages stuck in your mail queue also. From memory, I believe you go into Servers > Sendmail > & Outgoing Mail). (I currently do not have any of this opened, thus writing from memory.) The thing that fixed the problem was changing the first option (in "Sendmail Options") "Send outgoing mail via host" FROM: 'DELIVERY DIRECTLY' (through the host), TO: 'the name of our ISPS SMTP server' (in my case it was mail.your.provider). In other words, I realized that for some reason, mail was not sending out to external addresses DIRECTLY through the host. Forwarding it to our provider, however, succesfully sends out the messages.
At the moment, I am not sure of the route that one would take via command prompt, since I did this via webmin. When I look into it, I will let you know. In the mean time, I hope I have answered your question(s).