Hello,

Have anyone exprienced this?

We have global users around the country and some emails never get delivered. Does anyone know how can one investigate this problem? I have asked the hosting tech support and they stated they have no problems with their mail server..

abc(at)xyz.com and efg(at)xyz.com sometimes have problem receiving, they have to send another time after knowing their email didnt get delivered. Customer(at)efg.com sent emails to abc(at)xyz.com, but still the receipient didn't receive..

Any clues?

Spam filters could have blocked it for any number of reasons (domain filter, IP filter, Bayesian filter).

Problems communicating between mail server IPs.

Problems with users configuring rules to delete emails from you (junk mail filters or rules themselves.)

Problem with DNS resolution on your server.

In other words, there are too many reasons to isolate it down to just one.

i agree with u

i agree with u

Okay. thanks for that; at least I got some knowledge regarding this topic.

So far, I had never encountered a problem on my emails.

Hope for the best of this technology.

Thanks for the reply. I have managed to solve some of the lost emails.

I found out that if you host with different host, some host tends to get lots of SPAM emails than hosting with the other? Anyone knows is it possible to check which IP address is in the 'spammer' list'?? And if dedicated IP address is better compared to shared IP address to resolve this issue?

Depends on past use of the IP address.

What you can do is check the various spam blocking services to see if your IP is listed (e.g. http://www.spamhaus.org/). Another thing you can do is do an IP search on MSN to see what other types of sites are known to be on that IP (syntax IPyour IP here)).\

For example:

http://search.sympatico.msn.ca/results.aspx?q=IP%3A65.163.13.168&geovar=70&FORM=R EDIR

These are a few of the sites on my server.

If you see results like the ones from the link below, you'll have to question the safety of your IP in general (OFFENSIVE LANGUAGE FOLLOWS, BUT WITHIN CONTEXT):

http://search.msn.com/results.aspx?q...y=12&go=Search

Hi,

An example of the email bounced by some offices in China as follow:

-----Original Message-----
From: postmaster@xxxxxx.com.cn [mailtoostmaster@xxxxxxx.com.cn]

Sent: 2007年3月7日 19:46
To: ong@xxxxxxx.com.cn
Subject: Undeliverable Mail

Delivery failed 20 attempts: phi@abc.com
Delivery failed 20 attempts: zen@abc.com


Original message follows.

Received: from 71b6af0c6e8e47f [121.35.110.217] by xxxxxx.com.cn with
ESMTP
(SMTPD32-8.04) id A231260CF2; Wed, 07 Mar 2007 10:23:45 +0800

I search http://www.webmaster-toolkit.com/spa...cker.shtml?ip= on the ip address 121.35.110.217 and I got this:

ordb.org 121
njabl.org 121.35.110.217 is in other dnsbls.
blitzed.org The IP address 121.35.110.217
five-ten-sg.com IP address 121.35.110.217 is listed here as china spam

can I say the reason for this email bounced is because the IP address of mail server of xxxxxxx.com.cn is consider as china spam? And abc.com mail server rejected the email from them?

all domains name are just examples.

I have a question here, is the IP address of a particular email user sending emails always fixed? Or it's dynamic?

Thanks!