To:
Robert Elz <kre@munnari.OZ.AU>
cc:
<dnsop@cafax.se>
From:
Mats Dufberg <dufberg@nic-se.se>
Date:
Wed, 7 Feb 2001 12:59:50 +0100 (CET)
In-Reply-To:
<3384.981544350@brandenburg.cs.mu.OZ.AU>
Sender:
owner-dnsop@cafax.se
Subject:
Re: Bogus nic.fr behavior
On Wed, 7 Feb 2001, Robert Elz wrote: > The two problems I'd particularly like to avoid are the valid looking > e-mail address that simply forwards to what appears to be a black hole > (some ISPs collecting huge collections of mail no-one ever reads, or > at least, never responds to). > > And worse, the very valid looking "user.registered.dom.ain" where > "registered.dom.ain" has an MX record that points to the ISP's e-mail > server, and everything looks well configured. > > Until you try and send mail to user@registered.dom.ain and get back > a bounce message "Relaying for that host denied"... It is very to validate an address of the reasons that you give above. You can take either of two approaches; you can skip testing, or you can test as much as is manageable. Making sure that it is a possible mail domain (either an A or MX) is quick. Making sure that there is an SMTP server takes longer time. Mats ----------------------------------------------------------------- Mats Dufberg dufberg@nic-se.se NIC-SE +46-8-545 857 06 Box 5774 fax: +46-8-545 857 29 SE-114 87 Stockholm http://www.nic-se.se/