RE: Validating email addresses

Your best way is to use the standard NSLOOKUP api's that you would for
retrieving an IP address when given a name.  I have some code that was
passed to me from Scott Klement thru this list.  Search the archives for
Sockets.  If you cannot find something I can send you the Prototype and API
usage in RPGLE.  That will enable you to validate the domain and even lookup
the MX record(s).  You can then connect to port 25 of the returned IP and
follow the RPC for mail conversations.  You can then attempt to connect and
validate the mail ID without sending an e-mail.

Christopher K. Bipes          mailto:ChrisB@Cross-Check.com
Operations & Network Mgr  mailto:Chris_Bipes@Yahoo.com
CrossCheck, Inc.                http://www.cross-check.com
6119 State Farm Drive         Phone: 707 586-0551 x 1102
Rohnert Park CA  94928      Fax: 707 586-1884


-----Original Message-----
From: David Gibbs [mailto:dgibbs@mks.com]
Sent: Thursday, April 25, 2002 2:18 PM
To: midrange-l@midrange.com
Subject: Re: Validating email addresses


Perfect example: If John Ross's AS400 (the one that hosts midrange.com) were
to go dark (I know, it's an AS400, they never go down), you could still send
me email, as mail is being received by another system (just so happens to be
linux.midrange.com).  In fact, if linux.midrange.com were to go dark, and
John's AS400 stays up, there is might be *NO* way to send me email because
the MX system isn't receiving it (that's not the case, as I'm about to
explain).

Additinoally, in the current configuration, both midrange.com and
linux.midrange.com could go dark and you could STILL send me email, because
I have a backup MX that will receive and hold the mail.

Some backup MX's just hold the email for later delivery (mine delivers by
UUCP), but others are true mail system that a person would have to read
independantly.

1. Anyone who outsources their email.
2. Anyone who has a backup MX