cannot send to certain email addresses?

[sacramentum666]

I have a WINNT 4.0 sp 6a SBS server with exchange server 5.5 sp4 the problem that i am getting is that i cannot send email to certain addresses it started with only one person to certain address then other users started to get the same problem. they can send and received to other address with no problem. any ideas

thanks for the help

Sal gil

 

[cmeagan656]

It could be that the addresses that you are attempting to send to require that you have a reverse DNS (PTR record). You can check if you have one here

http://www.dnsstuff.com/

(enter your mail server IP address in the Spam Database Lookup - top of second column).

If you don't have a PTR record then contact your ISP.

Cheers.

 

[gescobedo]

I have the same issue.
I can't send emails to certain email addresess or domains.
Everything was working fine yesterday.

I checked my PTR record and it is fine.

What else can I look for to fix this issue?

 

[gescobedo]

I have the same issue.
I can't send emails to certain (several)email addresess or domains.
Everything was working fine yesterday.

I checked my PTR record and it is fine.

What else can I look for to fix this issue?

Tis is the error message I get:

Unable to deliver the message due to a communications failure

Host Unknown

 

[NetIntruder]

What is the error message you are receiving?

Have you checked to see if you are on a blacklist?

~Intruder~

"The Less You Do, The Less Can Go Wrong"

 

[sacramentum666]

i am listed on the list but only in australia does this mean that i still will be rejected and what can i do to get out of this list also my server no longer fowards mail to anyone i turned that feature off long time ago i will eventually be moving to exchange 2000 will this problem will be fixed

thanks

sal

 

[NetIntruder]

To get off the list, you need to close down relaying and contact the provider of "the list" - they will verify that you are no longer providing anon relay to the rest of the world and remove you accordingly.

As far as not being able to send to certain domains... how's your DNS topology? Do you use the root hints or do you point to your ISP? Can you telnet to the mail server you are trying to hit?

~Intruder~

"The Less You Do, The Less Can Go Wrong"

 

[sacramentum666]

i am pointing to my provider for the dns settings and yes i can telnet to the ip address i am trying to hit and thanks for the advice i will let the list provider know that i am not doing any relaying.

thanks for the help.