I haven't run a serious mail server for a while, but during the SMTP exchange, doesn't the receiving MTA host validate the IP address of the sender? And doesn't that show up in the envelope header? For example: EHLO localhost.localdomain 250-mailhost.yourdomain.com Hello realname.spam.com [ 192.168.0.9 ], accepting invalid domain name This could be one way to check, write a script that does a reverse IP lookup to see if the supplied name during the EHLO or HELO exchange matches the given name. I'm also pretty sure that there is an m4 configuration setting in the sendmail.mc file that disallows all "invalid" domain names. BAZ BRYAN ZIMMER ----- Original Message ----- From: "David Phillips" <electrum at gmail.com> To: "TCLUG Mailing List" <tclug-list at mn-linux.org> Sent: Tuesday, September 14, 2004 8:21 PM Subject: Re: [TCLUG] Verify senders email addy? > On Tue, 14 Sep 2004 16:44:05 -0500, John T. Hoffoss > <john.t.hoffoss at gmail.com> wrote: >> VRFY is part of SMTP, but many disable this on their server > > I have NEVER seen an active server that supports VRFY. > > -- > David Phillips <david at acz.org> > http://david.acz.org/ > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > Help beta test TCLUG's potential new home: http://plone.mn-linux.org > Got pictures for TCLUG? Beta test http://plone.mn-linux.org/gallery > tclug-list at mn-linux.org > https://mailman.real-time.com/mailman/listinfo/tclug-list > _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota Help beta test TCLUG's potential new home: http://plone.mn-linux.org Got pictures for TCLUG? Beta test http://plone.mn-linux.org/gallery tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list