Re: Validating email addresses

I am not sure you understand the purpose of the MX record. It is for mail,
it tells which server(s) is handling the email. When I say domain  I should
of said web server (WWW). If you ping midrange.com it will check the AS400.
If you ping linux.midrange.com it will check the first mail server. But you
have no idea from david@midrange.com to ping linux.midrange.com, without
looking up the MX record.

If you are dealing with businesses the olds that the business will
disappear is slim, where account@somebusiness.com disappearing is greater.
So to check just that the mail server is valid is pretty worthless (and
checking the web server is worse), you need to check the account to make it
worth your time.

This web site  http://www.zmailer.org/mxverify-cgi.html  is doing just what
I said you need to do. The DNS yields following MX entries
sections finds the MX records. The Testing server at address section does
the SMTP part. That web page checks more then MX records it checks email
addresses.

IBM can not block the SMTP protocol, if they did they would not get email.

Here is a test you know midrange.com  uses linux.midrange.com  for its
first MX record.
Find out your IP address,   http://www.mrmug.org/examples.html  near the bottom
Now start your favorite telnet client, connect to linux.midrange.com on port 25
when connected key in
HELO your ip-address
MAIL FROM:<>
RCPT TO:<john@midrange.com>
RCPT TO:<david@midrange.com>
QUIT
If you get a response that starts with a 5 it is not going to accept mail.
You can get an 5 for more then just invalid, the mail box might be full.

Note you can send email this way, use the following after RCPT TO: and QUIT
DATA
body of email
enter
.
enter

a . (period has to be sent all by itself to end the body of the email)

John Ross
At 03:57 PM 4/25/2002 -0500, you wrote:
>This is a multipart message in MIME format.
>--
>[ Picked text/plain from multipart/alternative ]
>John,
>
>When you say that ping will only validate the domain name, but that I
>should use the other stuff, what more will that tell me?  For instance, if
>my email address is fred@xyz.com will it tell me that fred is a valid
>address at xyz.com, or just that xyz.com does process email and is not
>strictly there for web pages or some such thing?
>
>I am trying to figure out how much is enough.
>
>In my sample code the exception for ping was different if ping was blocked
>versus if it was a nonexistent host.
>
>I understand that monitoring for bounced mail might be the best way.
>However we will not be using a spamming address, but instead real people,
>or groups, in the corporation.  These people will have the responsibility
>to manually update the records storing the email addresses.
>
>I kind of like this web site for checking mx records.  Try it for
>dekko.com and then for ibm.com:
>
>http://www.zmailer.org/mxverify-cgi.html
>
>What this might be telling me on IBM.com is that I'd better be darn
>careful doing the 'Then you would have to use sockets to connect to the
>mail server, following the protocol for SMTP' or with IBM's security those
>might be blocked also.
>
>Rob Berendt
>--
>"They that can give up essential liberty to obtain a little temporary
>safety deserve neither liberty nor safety."
>Benjamin Franklin