Hello, my problem is that I can send mail but not receive it. I'm using red hat. It just stopped working, I did not change anything, there's someone else who could have changed something but he doesn't work here any longer.
I really need some help because this is my first job, I' ve been here just for a week, so I have no experience.

I was reading some sites and i did this:

If I write host -t mx mydomain.com
the answer is mydomain mail is handled by 5 mydomain.
I did telnet mydomain using the port 25 the answer was :

220 mydomain ESMTP Sendmail 8.12.8/8.12.8; Mon, 2 feb 2004 22:17:41 -0600

I hope it helps to understand my problem.
Thanks , Silvia

Umm, 220 mydomain ESMTP looks like an ok response to me. It is probably a problem with the sendmail settings. You mind posting your sendmail configuration?

In the site I was reading there says I should have a file named something like sendmail.cf and it was quite short, I only found 2 files on /etc named sendmail.cf.rpmnew and sendmail.cf.rpmsave, these files are really big, like 1400 lines each.
Do you still want me to post it?

Do you think my problem is, that this file (sendmail.cf) is missing?

Thanks!!

PD: If I wrote something wrong, please correct me, english is not my first language.

In RH9 you should follow the path: /etc/mail and you should have a few files in that directory. The most important ones for sendmail are sendmail.mc and sendmail.cf. The sendmail.mc file is what "makes" the .cf file. After making any changes you have to use the m4 engine and produce a new sendmail.cf file. If you don't have these folders and files then there is a good chance someone has tampered with the install. There are other files in the above named directory and they are also important but sendmail won't run at all if it doesn't have the config file. Repost with your directory listing and I'll try to help.

The files on /etc/mail are:

access, access~, access.db, access.rpmnew, domaintable, domaintable.db, helpfile, local-host-names, local-host-names.orig, mailertable, mailertable.db, makefile, sendmail.cf, sendmail.mc, statistic, submit.cf, submit.cf.bak, submit.mc, trusted-users, virtusertable, virtusertable.db, makefile

Thank you

Ok, it seems as though the files are there and for now lets assume they are working correctly. One thing you didn't say in your posting was if the person who is no longer there left as a disgruntled employee. If so, it is possible that they made some changes before they left. If not, then something else is wrong. I had a simnilar occurance with a client; they could sendmail but could not recieve it. Is this a public server? Do you have the clients set up in the access database? It is the one titled "access". It should have a listing of allowed hosts that can relay through the mail server. Also, are you trying to mail from the server or from another box? Let me know the answer to these and we'll go from there.

The file access has the list of hosts allow to relay from the server. We use this server for mail and for our site too (Is that public?). I just tried sending a message from the server and I received it, if I try from another computer, I don't receive it.

Thanks again, Silvia

If this server is for your web site then it is public. Public meaning that it is accessible from the internet. Your other pc's are probably behind a firewall and on a private network. In the access list, is your network listed? Example, if your machine's (not the server's) Ip address is 123.456.789.012, there should be a listing in the access file that says:
123.456.789. RELAY
This means that all machines on this subnet are allowed to relay through this server. Obviously, the IP addresses above are bogus and just for example. Check and see if your network address is listed. By you being able to send and recieve from the server that is a good sign. That means that sendmail is working like it should. Now we just have to figure out why the clients aren't able to access it.One quick thing to check out is lets make sure that some other things are running. From the GUI, click on services. You'll have to give the root password. I don't know if this is a POP or IMAP server, but go down the list of services running and check to make sure that whichever one you are using is running. If not, click on the box on the left and click on "Start". Check on these things and repost.

The server uses POP3, my IP address is on the list like this>

163.178.89. . . RELAY

I'm really sorry to bother you but where exactly is" services"

Services are the daemons/applications running in the background. They facilitate your applications. For instance, the service "xinetd" is the one that is a major daemon and what listens to all of your ports looking for a request/connection. When it gets a certain call, it opens that port and connects the application. It can be found from the menu bar. Click on the redhat and go up to "System Settings", then "Server Settings" then click on services. This can also be done from the command line but can be really confusing. This is a much more straight-forward way. The entry in your access file looks correct (as long as it matches what actually exists on your network). What email program are you running on your clients and what OS? And by the way, it's no bother! I have been in your shoes and it's not a comfortable feeling. I am far from knowing everything and still learn on a daily basis; but, if I can pass on what little I do know then that is a good thing.

When checking services, make sure that sendmail and ipop3 are checked and running. If not, then start them.

I think they are running, the clients use windows and usually outlook or outlook express to check their mails, we also have a webmail. I just send a mail from my hotmail account and i received it, but i can only check it on the linux server.

Ok. Lets check some other things. 1) When you try and check mail from your client, what kind of error does it come back with? 2) What does the sendmail log have? To see this go to a command line and type "tail -F /var/log/maillog" and hit enter. No quotation marks. This should give you a real-time output of the mail log. When you see it running, go and check your mail from the client. It should reflect that you checked it but there was an error. (Hopefully) 3) Is your machine running iptables or ipchains? These are firewalls and can be configured to reject any connection on ports 25 or 110. So that may be turned off. You never said if you thought this could have been done by someone or not. Trying to analyze what is going on can be difficult if it was done maliciously.