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A co-worker comes back from lunch and notices that he hasn’t received any new e-mail in his inbox while he was away. He walks over and asks another co-worker if she is having the same problem. Pretty soon, about ten people walk over to confront you, the information technology coordinator. You immediately pick up the phone to call someone, but who?

In this multi-part series, I’m going to be covering the steps to take to isolate your e-mail problem so that you know which vendor to call. I will be focusing on companies that don’t have their own information technology team, but rather a coordinator that simply calls the appropriate vendor to resolve an issue. However, if you have your own e-mail server administrator, this information should also prove useful.

Empower your co-workers to continue working

Before calling anyone, you need to make sure that your co-workers need what they need to continue working and you also need to determine which vendor to call.

Ask the ten people if they are sure that someone has sent them an e-mail message. More than likely no one will be sure, and they’re pressuring you over a suspected problem. Even if someone is expecting an e-mail message, it doesn’t guarantee that the “missing message” was sent. While the co-workers are there, ask if anyone got an error when checking their e-mail. If they got an error, more than likely your e-mail server is down or the users that got errors are having problems with their workstations.

Also try sending an intradomain e-mail by sending an e-mail from someone at your domain to someone at your domain. If this doesn’t get sent successfully and arrive successfully, almost certainly there is a problem with your e-mail server or the network where it is hosted. We’ll be testing connectivity in part two of this series.

If there were no errors, and there simply wasn’t any e-mail when people check their inboxes, test your Internet connection and client DNS while your co-workers are still standing there. Usually just visiting a few Web sites that you hadn’t visited that day should suffice. If you have no problems with that, excuse your co-workers.

You can tell your co-workers, “You can still compose e-mail messages, even if our e-mail server is down and they get temporarily stuck on your computer with no where to go. If you are expecting an e-mail message that you need to continue working, please try giving the sender a telephone call. I will look into the suspected problem and let everyone know what I find”.

If some users are getting errors, and others aren’t getting errors but haven’t received any e-mail you may have two problems or maybe no e-mail has been sent to your users and the only problem is with the few encountering errors. Either way, you need to write down the error messages and either look in the documentation for the program giving the error, or contact the vendor of the program.

If everyone is getting errors, more than likely your e-mail server is experiencing problems. You will want to contact your e-mail server vendor. You may be able to walk over to your e-mail server and see if there are any errors on the console, and you’ll likely need to be at the console when you call the vendor, anyway.

Did you make any recent changes? 

If no one is encountering errors when checking their e-mail, we need to do some more digging. More than likely your e-mail server is no longer offering e-mail service to the public in order to receive new e-mail messages. We need to isolate the cause of the problem.

Did you make any recent changes to your domain name system records? The doman name system, also known as DNS, resolves mnemonic computer names to Internet addresses. Your Internet e-mail and Web site rely on DNS working correctly.

Did you recently change Internet service providers, or web/e-mail hosting providers? Did you make any changes to your firewall or e-mail server? If you don’t manage your own e-mail server, did the company that manages it make any changes? It’s common for companies to make changes that they don’t think will have any impact on your services, without notifying you.

Recent means when the suspected problem started occuring. If you recently had changes made, you may want to consider having them undone or you can have the new configuration worked on until it is functioning correctly.

Sending the test message

Contrary to popular belief, logging into your free web based e-mail account and sending a test message is not a reliable test method. In fact, free e-mail services are well known for delaying or losing e-mail messages. However, you still want to send a test e-mail message to yourself from somewhere outside your network and outside the network where your e-mail server hosted.

If you use a free e-mail service, use at least two of them to send multiple test messages. Note that sending a test message is not a good way to test a problem because it will rarely provide useful information, but it can rule out a problem. If you get the test message, and quickly, you’ve confirmed that there isn’t a problem, at least not affecting everyone.

If you send a test message and get an immediate notification of a delivery failure, the notification should have verbose information to help you determine whether your domain’s e-mail server rejected it, or the sending server rejected it. You should then contact the e-mail server administrator of that e-mail server.

Did your domain name expire?

One of the many reasons why a domain stops getting e-mail is because they mistakenly let their domain name expire. The domain name is the part in your e-mail address after the at symbol. You can see if you domain name expired by doing a whois on it. If you have access to an Internet connected UNIX/Linux server, you can use the following command if you have ”whois” installed, which is likely. Replace “example.com” with your actual domain name.

whois example.com

If you don’t have access to a whois program, you can use many of the free web based ones, such as the one at domaintools.com.

If your domain name has expired, you will want to contact your domain name registrar to renew your domain name. The results of the whois program should tell you the name of the registrar if you don’t remember where you registered your domain name.

Checking your domain’s DNS MX records

Your domain’s MX records tell the world where to send e-mail for your domain. To check them, you can use the “dig” program that comes with the Berkely Internet Name Daemon, also known as BIND, on UNIX/Linux. If you have a server running this software, you can use the following command, where “example.com” is replaced with your actual domain name.

dig example.com. MX

The results will indicate the mail exchangers where people should be sending e-mail for your domain. The resultant MX records should list your e-mail server’s hostname or your e-mail gateway’s hostname, such as your anti-spam service.

You may get back an answer like this:

example.com.  600 IN MX 5 mail.example.com.

The name of our e-mail server in this example is “mail.example.com”, so this is correct.

The next step is to make sure that the name of your e-mail server resolves to the server’s Internet address, to prove that the DNS is working correctly. You can do this with the following command on a UNIX/Linux server, where “mail.example.com” is replaced with your e-mail server’s name.

dig mail.example.com. A

You should get back an answer with your e-mail server’s numeric Internet address. If the address is incorrect, or the MX record from the previous step were incorrect, contact your DNS provider.

If you don’t have access to a UNIX/Linux server, you can use the “nslookup” command on Windows by opening a Command Prompt and typing these commands instead of the above two:

nslookup -query=MX example.com.
nslookup -query=A mail.example.com.

The next article in this series will continue isolating the problem.

Next article in series: “Testing your e-mail service: Part 2“