There are a lot of things it could be. The logical thing to do is to take
the same path that the message would.
Open an ssh session over to the server that is sending the mail and 'su -
name' to whatever account it is that the messages are being sent from.
First, try to resolve the hostname via whois/host/dig or whatever tool it
is that you can use to determine the IP address of the host. Does it match
what it is supposed to? I've seen people try to plug a host name into a
mail client, and then inadvertently hit the wrong server because the IP of
the box had changed out due (fail over and cached records can be a pain.
Yeah.. I know. It shouldn't happen, but...)
If you are sure that you have the correct address and hostname, then try
telnetting to the smtp port on the remote mail host. Something like this:
telnet remote-host-name 25
should get you connected. Now, the remote server, depending on the mail
package that is being used and how it is configured may or may not display
a banner for you to see. If it does, wonderful. If not, also wonderful
because it means that the remote mail adminstrator did his homework and
knows that the banner is one less piece of information to give the bad
guys.
Speak the SMTP protocol. It's simple:
Introduce yourself to the server:
HELO your-host-name
The server, if it like you should respond with something like this:
250 Hello, your-host-name. I am pleased to meet you.
Now, tell the server who the mail that your sending is from:
MAIL FROM: <[EMAIL PROTECTED]>
If you are allowed to send mail or rather the server has been configured
to accept mail from your domain, it should respond with something like:
250 Sender OK.
Next, tell the remote mail host who you are sending the message to:
RCPT TO: <[EMAIL PROTECTED]>
If there is nothing wrong with the remote mail box/account, and the
account exists, it should say something like:
250 Recipient OK.
Tell the server that we have a message to send:
DATA
The server should respond with:
250 Begin message. Send a "." on a line by itself to close message.
Now - enter a test message that should be received by the remote user or
account.
Subject: Mail Test
This is a test.
.
At this point, the server should accept the message into the local mail
queue on the server for delivery. If there are no issues, you should see
something like this.
250 Message accepted for local delivery.
Now, be a nice net person and close the connection the proper way.
QUIT
The server will close the connection.
I am going from memory here so the error codes themselves might vary a
little bit. Any error messages should be seen with a 500 code. If there
are any Spam filters, of gray listing milters installed, they should show
a message during your session (unless they have been configured to filter
content later which - IMHO - is tacky).
If all of this works, call the remote administrator and ask him to check
his mail log. If anything wierd is happening, like the remote server is
out of space on the mail or log volumne, it should show an error in there.
If worse comes to worse, due what I like to do - go to the remote server
with pair of crash paddles and hit it with 250,000,000,000,000 volts.
Offered humbly.
> I just had a situation where a customer could receive email from my
> Outlook account but could not receive information sent directly from our
> Unix server (where ARS is running) through sendmail. He add to include
> our server in his "safelist". Don't know what type of mail system or
> mail filtering system he is using.
>
>
>
> Dan
>
>
>
> Dan Wangler, Team Lead, STARS Group
>
> Phone: 214-567-8304; email: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
>
> Client/Server Services, IT Operations
>
> Texas Instruments, Inc.
>
> 6500 Chase Oaks Blvd., MS 8401
>
> Plano, Texas, 75023
>
>
>
>
>
> From: Action Request System discussion list(ARSList)
> [mailto:[EMAIL PROTECTED] On Behalf Of Phil Murnane
> Sent: Thursday, April 24, 2008 10:46 AM
> To: [email protected]
> Subject: Re: One company not able to recieve emails
>
>
>
> **
>
> Chris:
>
>
>
> In the past, I've seen spam filtering cause organizations to not receive
> Remedy email alerts. It might be GroupWise itself or it may be some
> integrated security application (eg, Norton/Symantec).
>
>
>
> HTH,
>
> --Phil
>
>
>
> ----- Original Message ----
> From: "Moore, Christopher Allen" <[EMAIL PROTECTED]>
> To: [email protected]
> Sent: Thursday, April 24, 2008 6:14:05 AM
> Subject: One company not able to recieve emails
>
> **
>
> Hey everyone-
>
>
>
> We support 27 different ¡companies¢ (state agencies) and the users for one
> of them is not receiving any email notifications from Remedy. Emails are
> being sent without errors from our end- as far as we¢re able to see they
> were successfully delivered. Other agencies are receiving emails. At
> this particular agency they don¢t use Exchange, they use Groupwise. I
> have never heard of that until this morning- does anyone have any
> experience with it and know if it¢s possible it could be the culprit?
>
>
>
> Thanks,
>
> Chris
>
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> --
> This message has been scanned for viruses and
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> believed to be clean.
>
>
--
-------------------------------------
Will Du Chene
-------------------------------------
[EMAIL PROTECTED]
http://www.myspace.com/wduchene
-------------------------------------
"...you're an anti-Microsoft zealot..."
- Norm Kaiser
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