Re: Email verification (was: [PHP] Removing Invalid Users)

"Steve Werby" <steve-lists@befriend.com> writes: > "Arcady Genkin" <a.genkin@utoronto.ca> wrote: > > If I understand correctly, vrfy does not wholy depend on that > > functionality to be supported by the server. I think that it simply > > connects to the smtp port of the mail exchanger and emulates an email > > delivery, aborting halfway. > > I hadn't used the tool until after this thread started, but it appears it > uses the vrfy command when checking an email address, other flags let you > check a domain's mx record or attempt to use the etrn command. [...] > IMO, it makes more sense to use PHP's built in functions that can do > the same, but YMMV. vrfy does appear to be a decent tool, my point > was that when checking email addresses (not domains) most servers > will deny the vrfy command and so it won't be very useful. In fact, > I tried a number of different email addresses on different hosts and > all reported "Command Unimplemented". You are right, by default the proggie is not very useful. The "-n" option is probably of the most utility: -n Many non-sendmail hosts do not, or incorrectly or incompletely, implement the VRFY command. Other systems have VRFY or EXPN disabled for privacy reasons. This option uses an alternative protocol suite with the regular HELO, MAIL, RCPT and RSET commands. This gives only a global indication whether the recipient is valid. Recursive mode is not possible, and will be disabled. I've tried it with a number of email addresses, and it worked. Of course, this can be coded in the PHP script, but it would require elementary knowledge of SMTP protocol and more code to debug and maintain. For many people relying on an external utility like that may have more advantages. -- Arcady Genkin i=1; while 1, hilb(i); i=i+1; end