[Mailman-Developers] Suggestions about Mailman bounce processing

[Superticker2 (Mark)]

Trying to verify the email address prior to the Mass Subscribe/Invite is
the easiest solution.  I'm going to look into that first. Thanks for all
the tips below.

But as pointed out below, because of spammers trying to randomly guess
email addresses, I think today's mail servers don't always respond with
reliable answers.  This makes address verification problematic, although it
can't hurt to try finding some of bad addresses that way.

Sorry, I haven't learned PHP as yet.  My most fluent programming languages
are C, C++, G (LabView), and MatLab.

Happy computing, Mark


*********** REPLY SEPARATOR  ***********

On 12/28/2010 at 3:29 PM Mark Sapiro wrote:

>Superticker2 (Mark) wrote:
>>
>>If there's a service or utility that can verify a list of email addresses
>>(prior to a mass operation), please suggest it.
>
>
>There are some. See for example
><http://www.tienhuis.nl/php-email-address-validation-with-verify-probe>
>or try this google search
><http://www.google.com/#q=verify+email+address>.
>
>There are problems with trying to do address verification without
>actually sending mail. The obvious way to verify an address is to send
>an SMTP VRFY command to the MX of the domain of the address, but these
>days most SMTP servers either don't implement VRFY or won't accept
>VRFY from untrusted sources.
>
>The alternative is to begin an SMTP dialog with the MX and send MAIL
>FROM and RCPT TO commands. As long as you don't send DATA, no mail
>will actually be sent, but this is not reliable. If the MX rejects the
>RCPT, you may know from the status that the address is bad, but some
>MXs will accept an invalid RCPT address and not respond with failure
>until after DATA, and you can't continue to that point if you don't
>want to actually send mail.
>
>
>For example, consider the following two SMTP sessions
>
>$ telnet a.mx.mail.yahoo.com 25
>Trying 67.195.168.31...
>Connected to a.mx.mail.yahoo.com (67.195.168.31).
>Escape character is '^]'.
>220 mta178.mail.ac4.yahoo.com ESMTP YSmtp service ready
>HELO msapiro.net
>250 mta178.mail.ac4.yahoo.com
>MAIL FROM: <mark at msapiro.net>
>250 sender <mark at msapiro.net> ok
>RCPT TO: <totally_bogus_mark_sapiro at yahoo.com>
>250 recipient <totally_bogus_mark_sapiro at yahoo.com> ok
>DATA
>354 go ahead
>.
>554 Transaction failed: empty DATA not allowed
>Connection closed by foreign host.
>
>and
>
>$ telnet a.mx.mail.yahoo.com 25
>Trying 67.195.168.31...
>Connected to a.mx.mail.yahoo.com (67.195.168.31).
>Escape character is '^]'.
>220 mta112.mail.ac4.yahoo.com ESMTP YSmtp service ready
>HELO msapiro.net
>250 mta112.mail.ac4.yahoo.com
>MAIL FROM: <mark at msapiro.net>
>250 sender <mark at msapiro.net> ok
>RCPT TO: <totally_bogus_mark_sapiro at yahoo.com>
>250 recipient <totally_bogus_mark_sapiro at yahoo.com> ok
>DATA
>354 go ahead
>From: me
>To: you
>
>body
>.
>554 delivery error: dd This user doesn't have a yahoo.com account
>(totally_bogus_mark_sapiro at yahoo.com) [0] - mta112.mail.ac4.yahoo.com
>Connection closed by foreign host.
>
>-- 
>Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
>San Francisco Bay Area, California    better use your sense - B. Dylan