cjhaydon
06-18-2006, 02:30 AM
Hi All
First time here.
Have exchange 2000 running for small company.
Server gets to the internet via our router/adsl modem.
Our ISP provider is a company called TPG.
I can send email to everyone in the world, EXCEPT for people whos email address is someone@TPG.COM.AU
Now, this ONLY started happening 2 months ago.
The ISP instigated a null check thingy to supposidly stop spam (ref below).
What do i need to do, to fix this particular problem
-Cheers
Craig
====================
message from TPG help desk
===============
In the last few months, we enabled sender address verification so that we will only accept mail from verified e-mail addresses. By verification, we mean e-mail addresses which does exist and will accept mail in return. This is to help reduce the amount of unsolicited bulk and/or commercial e-mails (or more commonly known as spam) and viruses from being sent to our users.
The way it works is that before accepting a message, we perform an SMTP callback to one of the Mail eXchanges (MX) listed for the sender's domain. We then use the delivery status notification address, which is the null envelope sender address (<>) used for error reporting, to verify the existence of the e-mail address used by the sender and check to ensure that it will accept mail in return.
If the callback is successful, that is - the selected MX for this domain replies saying that the sender's e-mail address does exist and will accept mail for this address, then we will accept the message and deliver it accordingly.
If the selected MX for this domain refuses to accept mail for the sender's e-mail address, then the message is rejected by our mail servers with the appropriate error as provided by the selected MX.
Technical notes for mail server administrator
To verify a message's sender address, our mail hub will attempt the following...
* check that the header is syntactically correct
* attempt to find a mail server for the domain part of the sender address (based on either MX or A records)
* open an SMTP connection to that server
* send the following:
HELO our-server-name
wait for success response
MAIL FROM: <>
wait for success response
RCPT TO: sender-address-from-your-message
wait for success response
QUIT
If any step fails, the message will be rejected.
Note that the dummy mail is sent as if it were a bounce receipt, thereby testing whether a bounce message is deliverable to that address.
If your server does not allow bounce receipts, it is not functioning correctly. Please read RFC2821 (in particular, sections 4.1.1.2 and 3.7) and ensure that your mail server complies with the RFCs.
First time here.
Have exchange 2000 running for small company.
Server gets to the internet via our router/adsl modem.
Our ISP provider is a company called TPG.
I can send email to everyone in the world, EXCEPT for people whos email address is someone@TPG.COM.AU
Now, this ONLY started happening 2 months ago.
The ISP instigated a null check thingy to supposidly stop spam (ref below).
What do i need to do, to fix this particular problem
-Cheers
Craig
====================
message from TPG help desk
===============
In the last few months, we enabled sender address verification so that we will only accept mail from verified e-mail addresses. By verification, we mean e-mail addresses which does exist and will accept mail in return. This is to help reduce the amount of unsolicited bulk and/or commercial e-mails (or more commonly known as spam) and viruses from being sent to our users.
The way it works is that before accepting a message, we perform an SMTP callback to one of the Mail eXchanges (MX) listed for the sender's domain. We then use the delivery status notification address, which is the null envelope sender address (<>) used for error reporting, to verify the existence of the e-mail address used by the sender and check to ensure that it will accept mail in return.
If the callback is successful, that is - the selected MX for this domain replies saying that the sender's e-mail address does exist and will accept mail for this address, then we will accept the message and deliver it accordingly.
If the selected MX for this domain refuses to accept mail for the sender's e-mail address, then the message is rejected by our mail servers with the appropriate error as provided by the selected MX.
Technical notes for mail server administrator
To verify a message's sender address, our mail hub will attempt the following...
* check that the header is syntactically correct
* attempt to find a mail server for the domain part of the sender address (based on either MX or A records)
* open an SMTP connection to that server
* send the following:
HELO our-server-name
wait for success response
MAIL FROM: <>
wait for success response
RCPT TO: sender-address-from-your-message
wait for success response
QUIT
If any step fails, the message will be rejected.
Note that the dummy mail is sent as if it were a bounce receipt, thereby testing whether a bounce message is deliverable to that address.
If your server does not allow bounce receipts, it is not functioning correctly. Please read RFC2821 (in particular, sections 4.1.1.2 and 3.7) and ensure that your mail server complies with the RFCs.