mail server configuration

[Jessica Chou]

please help!
At what kind of situation that some certain mail servers can not receive mails from my mail server?
When I sent mails out, no matter if I sent it through a client-side email software(SMTP) or directly telnet to my email server to sent it with "sendmail", I couldn't get it.
First, I got warning message as:
quote:
The original message was received at Fri, 19 Jan 2001 16:18:26 +0800
from xxx.yyy.com.tw [1.1.1.1]

----- The following addresses had transient non-fatal errors -----



----- Transcript of session follows -----
,... Deferred: Connection reset by mx.pchome.com.tw.
... Deferred: Connection timed out with ethome.com.tw.
Warning: message still undelivered after 4 hours
Will keep trying until message is 3 days old

unquote********************

after few more warning emails being sent to me, I got the "Returned mail: Cannot send message within 3 days" which contained:

The original message was received at Fri, 19 Jan 2001 16:18:26 +0800
from xxx.yyy.com.tw [1.1.1.1]

----- The following addresses had permanent fatal errors -----



----- Transcript of session follows -----
... Deferred: Connection reset by mx.pchome.com.tw.
... Deferred: Connection timed out with ethome.com.tw.
Message could not be delivered for 3 days
Message will be deleted from queue

unquote
************

I can receive mails from "pchome" or "ethome" though.

Any configuration I need to check?
Thank you very much for your help.

[Jerry U]

To check to see why you can't send mail, start with these steps.

The email address.
Use sendmail -bv user@host to verify the email can be sent. For example,

/usr/lib/sendmail -bv juanino@yahoo.com

juanino@yahoo.com... deliverable: mailer esmtp, host yahoo.com., user juanino@yahoo.com

Then, check the host MX record. i.e., try nslookup -q=mx yahoo.com

You will see many lines like:
yahoo.com preference = 4, mail exchanger = mx4.mail.yahoo.com
yahoo.com preference = 6, mail exchanger = mx6.mail.yahoo.com

Then try to telnet on port 25 to each of the mx4.mail.yahoo.com's (or whatever shows up for you).

Come back to this form if you can get to them on port 25, if not, you may have a firewall issue.

[Jessica Chou]

sendmail -bv xxx@pchome.com.tw
replied me
"deliverable: mailer esmtp, host hotmail.com., user xxx@hotmail.com"

then i nslookup -q=mx pchome.com.tw
and got the mail exchange server as
mx.pchome.com.tw

So, i
telnet mx.pchome.com.tw 25
and didn't get through. It said that
"Connection closed by foreign host."

I tried this from a server outside, and it
can get connection on port 25 to mx.pchome.com.tw.
so, what's the next step I need to do in
order to fix the firewall issue?

Thank you.

Jessica

[Joseph C. Denman]

Can you get out with anything (such as web browser or ftp) from this host? If not, you may not have your default gateway setup.

Something to look at?????

If it is the firewall, just set up a proxy to allow port 25 out.

jcd...

[Jerry U]

ok. so you are being shut out from mx.pchome.com.tw on port 25. Do you own this box? You can take a look at the log files on the mail server and see why you are getting shutdown.

It is probably *not* a firewall issue because that connection refused message is actually coming from the sendmail server on that mx.pchome.com.tw box. I would guess it is rejecting access from you because you don't have a real ip address or your ip address is blocked from that machine (via tcpwrappers or something). I can connect to it from one machine but not from another.

Do you know the admin for that mail box? They may have an anti-spam feature that is blocking you.

j

[Shannon Petry]

I agree, and have had similar server setups intentionally to block SPAM. (I block hotmail because it is a spam door {provided by our friends at Microsoft})
If you can see the MX record for the domain, ping the machine, your mail address is valid then you have a block for port 25 setup on that server.
Since your mail address is valid either your IP, hostname or domain name is blocked because it does not let you get to the point of authenticating your address.

Give them a call on the phone if you really need to send them mail.

Shannon

[Jessica Chou]

I see.
So, I guess I will talk to our ISP first to see why our IP would be blocked.
It's great to at least identify what the problem is.

Thank you all.

Jessica