On Mon, 28 Dec 2009 00:39:35 +0100 Ansgar Wiechers <li...@planetcobalt.net> wrote:
> On 2009-12-27 John Peach wrote: > > On Sun, 27 Dec 2009 23:34:47 +0100 Ansgar Wiechers wrote: > >> Perhaps I'm missing something, but I fail to see the big difference > >> when it comes to address verification. Regardless of whether you use > >> VRFY or MAIL FROM/RCPT TO/QUIT, if the address is invalid the > >> response will be > >> > >> 550 5.1.1 <address_to_be_verif...@example.net>: Recipient address > >> rejected > >> > >> If it isn't, the address can be considered verified. Unless, of > >> course, the server produces backscatter. Which it shouldn't. > > > > No it is not. > > > > 502 5.5.1 VRFY command is disabled > > > > just tells you that VRFY has been disabled; not the validity of the > > address. > > You're missing the point. When you find that VRFY is disabled, you'd > simply use > > MAIL FROM:<a...@example.com> > RCPT TO:<address_to_be_verif...@example.net> > QUIT > > instead of VRFY. > > If the server doesn't produce backscatter (i.e. accepts first, bounces > later), the result of the above sequence will tell you whether or not > <address_to_be_verif...@example.net> is valid. I'm not missing the point - simply explaining why most sites disable VRFY and that it is not the same as mail from:; rcpt to: Admittedly, it makes very little difference these days, but in the late 90s/early 2000s it was one tool in the box. -- John
