DNS Query Web Site - DNSSTUFF Not Working

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Toby

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I normally use DNSStuff to check out dns based problems from behind a firewall. However, always giving problems now.

Anyone know of a good web based site that will check out Dns for a supplied name and give an indication where settuing may be lacking
 
Yeah, this is because the SAIX transparent cache's that we are all forced through have been identified as trouble spots on the internet radar! :rolleyes:

Come to think of there are quite a few SAIX ip's that are thought of as abusive.
 
Any Ideas on this would be welcome

A section in our company sends out information by email. (Not Spam, but orders, queries etc)

I would like them to validate email addresses themselves, rather than flood , bother the help desk.

Typically.

Is the destination remote email address valid
Is the remote mailbox "full" Over Quotas and rejecting mail
Are the links to the remote Mail Server up.

I would like this to run behind a firewall.

Ideal would be to run a tool against a CSV or Excel Sheet of address.

Problem here is that most of the stuff i see on the net looks suspiciously like smtp address harvesting tools, and I do not want to risk them and get our domain blacklisted.

Any Ideas
 
Toby,

Your question is vague and I'm not sure i understand it fully, but i will try respond as best i can, and maybe you can expand a little :o

By saying you would like 'them' to validate emails themselves - this being your clients ? for the sake of the response, I'll assume that you mean clients.

Firstly validating - if full / over quota - is not easy unless you are directly manipulating mail headers and have another daemon running to capture bounces and record erroneous accounts.

You should assume that the links are up to the server and even if the link is temporarily down - a good SMTP server (your side) should keep the mail in queue and retry for a good few hours before finally failing.

Validating a mail addie should not just be that the remote server accepted the mail, a human response is the validating factor and should be required to authenticate that account as valid and that the person there is your intended recipient.

So what i suggest is mailing your client list (XLS, CSV, Database...) with a mail explaining that you are wanting to validate your database of records and could they please click this link to validate that they received the mail. This link should be a hyperlink to the company website or hosted somewhere and just record that that person is alive and "thanks for validating your email." Hosting this page on the company website will keep the whole process looking legit and not some Phishing attempt.

Another concern would be just making sure your mail server complies with all the necessary DNS requirements such as having a valid host name and reverse DNS set up. Is not an open relay and all the correct ports are open for traffic. Most remote mail servers will not accept mail unless it comes from a FQDN with reverse DNS lookups. Checks out with all the blacklists on the net. The remote server will also attempt to connect back to sending machine to validate things before allowing delivery (not all mail servers).

By running your mail server from behind a firewall you will be NAT'ing the connections through and if you haven't already set this up, it can be tricky.

I also highly recommend using standard mail-daemon software for any task and not some mail bomber, and would recommend an open source option such as Qmail or Sendmail running on BSD or Linux.

Let me add that applications bombing mail servers with mails addressed to people that either do or don't exist to test if the mail is accepted or not is SPAM and you'll find yourself blacklisted and possibly arrested if it is serious.

Hope some of this helps, if you want me to get specific on anything give me a shout.
 
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By saying you would like 'them' to validate emails themselves - this being your clients ? for the sake of the response, I'll assume that you mean clients
Click to expand...

Correct, We want the end user to Vaildate e-mail address's. Where a address seems suspect, the Help Desk does a Telnet in to Remote mail server on port 25 to check that it is valid and that the email address is valid

So what i suggest is mailing your client list (XLS, CSV, Database...) with a mail explaining that you are wanting to validate your database of records and could they please click this link to validate that they received the mail. This link should be a hyperlink to the company website or hosted somewhere and just record that that person is alive and "thanks for validating your email." Hosting this page on the company website will keep the whole process looking legit and not some Phishing attempt.
Click to expand...

Have you got an example of this, or links to a site that has example code and methodologies

You should assume that the links are up to the server and even if the link is temporarily down - a good SMTP server (your side) should keep the mail in queue and retry for a good few hours before finally failing.

Another concern would be just making sure your mail server complies with all the necessary DNS requirements such as having a valid host name and reverse DNS set up. Is not an open relay and all the correct ports are open for traffic. Most remote mail servers will not accept mail unless it comes from a FQDN with reverse DNS lookups. Checks out with all the blacklists on the net. The remote server will also attempt to connect back to sending machine to validate things before allowing delivery (not all mail servers).
Click to expand...

Our mail infrastructure has been checked and is sound

Let me add that applications bombing mail servers with mails addressed to people that either do or don't exist to test if the mail is accepted or not is SPAM and you'll find yourself blacklisted and possibly arrested if it is serious.
Click to expand...

This is my problem. - However, the email addys will be only addys submitted by the email addy owner. - (We find that they change, die, etc etc without the owner notifying us, with the result that we have a bad email addy) We send out order confirmations via mail, but if a reciepient does not get it, this becomes a problem. I would like a way of checking validity of mail addy without appearing to be a spammer or email addy harvester.
 
What you are after is the " Holy Grail! " :)

The email solution is nothing new, and it can be implemented in a variety of ways, using different programatical approaches.

For the sake of the explanation PHP web scripting will be employed and i'm going to assume that all your user info is stored in mySQL datasource.

Write a script or find a mailing script online HTML.mime.mail is a great fully featured script and a nice place to start, it can easily be extended for your needs, and i have used it for such a purposes in the past.

Roughly you should iterate over the data in your Database, and send off mails to the recipients, the script will create and encode HTML mails on the fly allowing you to embed a customised link into each mail, with the user_id of each user attached to a link.

Consider:

----- SNIP -----

Dear, John Smith

We are currently updating our digital records of our clients for the purposes of improving our services to you...

Please could you click the following link to verify that you have indeed recieved this mail.

http://www.mycompany.com/accountVerify.php?user_id=12465

----- END SNIP -----

The accountVerify.php script will just update your database to reflect that the user with id=12465 is valid, and echo back thanks very much!

Thats the general concept and most anyone with 1 or 2 years web scripting knowledge in PHP, JSP or ASP etc... will be able to write something like for you pretty quickly.

This concept can also be expanded to have a pretty browser driven web interface and other such niceties... ;)

I have just had a quick look on google and found some good reading:


Hope this helps and gives you a good starting point
 
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