Mail Delivery Subsystem

[stephen]

Dear all,

    We are having a RedHat Linux Mail Server (Ver 7.1) with 5 POP e-mail ids.We are having BSNL Broadband for Internet Connectivity.We have done masquerading for one Pop id and now a days we face a new problem with the Server.Our POP id with VSNL and We fetch all the mails from VSNL without any Problem.


For Example, When Sending a mail to india.com or some other id's, it rejects our mail and given the following error.

Error 554.5.0.0 that is"SERVICE UNAVAILABLE" WHILE TAKING TO "user@india.com".

The error gives some site for hyperlink and the site clearly shows the mail is a SPAM and it also gives that the SPAM  may be you or nearby ip u have.We have checked all the systems by a good anti-virus scanner and ther is no SPAM in our systems.

In this Case there is confusion on my mind,because there is no problem with sending some mail to yahoo,rediff,etc through Linux Sendmail and the same rejected mail can reach the india.com wtihout any problem when i send the mail through direct connection with bsnl broadband Router.
 
Anybody help me for solving this Issue.


Thanks in Advance,

Stephen.J

[Ricky]

Here you are saying that your mail get rejected while sending them when you are doing masquerading and you can still send them when you do that via router !

I found that your question is little unclear. I request you to kindly elaborat a little more , btw.. the message that sites shows means that the IP you are using to send your mail has been black listed . Don't take it serious.. its just wild guess.

[stephen]

Thanks for the reply.
 
      We are having mail server and the Redhat Linux version 7.2 is running on that.We have BSNl Broad band for the Internet Connectivity.
 

      Bsnl router is directly connected to to our network Switch.We put the Broadband router ip as a gateway to Linux Server for Internet Connectivity.
 
      We have 5 POP Id's from VSNL and we have configured in Linux Server and we are Masqueraded one POP id for our internal need.In Linux server We are using "Linuxconf" for configuration and we have done all the Fetchmail and Senmail on that.
 
      We are using Microsoft Outlook 2003 for Client and we are configured all POP ids and Masqueraded id's.There is no problem with Send/receive.
 
       Here in this setup,
 
1) when we send a mail to user@yahoo.com,user@rediff.com,user@ourdomain.com and some of other ids,the mail is travelling through Linux Server and ISP freely without any Problem and we can receive reply messages from the above ids without any problem.
 

2)When we send a mail to
user@india.com and some other id's we have received a sudden reply message like
 
554.5.0.0 while taking to user@india.com
Service is unavailabe
 
and it gives a hyperlink to one web-page and the Web page detail shown the mail may be a SPAM or a nearby ip what you are using may be SPAM.
 
So it rejects the mail,In this case i found onething the returned mail is from the ISP or may be ANTI-SPAM site and i receive the mail without fetching by Linux Server.

So we have checked all the systems by good anti-virus scanner for SPAM and there is SPAM in all our systems.
 
In this case,We send the same rejected mail through the direct connection to user@india.com and What all the messages rejected,  there is no problem with Sending and receiving.


In this case i found onething.My diagnoses are

1)The rejected mail is not rejected by Linux Sendmail.

2)The mail may be rejected by ISP or Anti-SPAM sites.

3)The mail is rejected to user without fetching by Linux fetchmail.

The Above details will help me to find the solution for sortingout this issue.


Thanks in advance......


Stephen.J

[Ricky]

In this case,We send the same rejected mail through the direct connection to user@india.com and What all the messages rejected, there is no problem with Sending and receiving.

What is that direct connection, is it without using linux ie connecting the PC directly to internet via bsnl ?

[stephen]

Thanks for the reply..

Yes..Without using Linux,We put a direct cable to bsnl router and there is no problem in sending/receiving.


Thanks in Advance,

Stephen.J

[stephen]

Dear all,

     I found the solution for the error with the help of my ex-collegue.
This is the Solution.....


1) When i send a mail to user@india.com thro' Linux server,Outside Firewall Checks my e-mail that contains a e-mail id but not a valid reverse lookup.

So my e-mail not having a exact reverse lookup,Some sites firewall considered my e-mail as a SPAM and get rejected to my linux mail server.

Then i put the SMARTHOST in sendmail.cf like

DS[my isp ipaddress]

Now i can able to send/receive all mails thro' my linux server.


In this case i have to clarify onething.

2)When i send a mail to user@india.com by a direct connection,i put the ip address of my isp in my outlook.So mails are not rejected by outside firewall because the reverse lookup is good from my ISP.


Thanks once again......


Stephen.J