Stephen Gran on 8 Aug 2004 18:39:03 -0000


[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: [PLUG] mail question


On Fri, Aug 06, 2004 at 09:42:57PM -0400, Jeff Abrahamson said:
> On Tue, Aug 03, 2004 at 10:57:44PM -0400, Stephen Gran wrote:
> > 
> > Verizon is hopeless - they do all sorts of broken things in an attempt
> > to slow the influx of spam, and one of their many tactics is to just
> > randomly defer email, it seems.  Another is to use pipelining in
> > callouts, even when pipelining is not advertised, so that your MTA
> > rejects (rightly) the connection, and then their MTA defers you.
> > 
> > Try the following (this is exim4 - things are differnet in exim3):
> 
> I have exim 3, but I tried some of what you suggested.
> 
> With debugging on, I see the conversation go like this:
> 
>     diderot:~# exim -d  -M 1Bt3Fm-0007Io-00
>     Exim version 3.35 debug level 1 uid=0 gid=0
>     Berkeley DB: Sleepycat Software: Berkeley DB 2.7.7: (08/20/99)
>     delivering message 1Bt3Fm-0007Io-00
>     Connecting to relay.verizon.net [206.46.170.12.25] ... connected
>       SMTP<< 220 sc006pub.verizon.net MailPass SMTP server v1.1.1 - 121803235448JY ready Fri, 6 Aug 2004 20:36:10 -0500
>       SMTP>> EHLO diderot.purple.com
                    ^^^^^^^^^^^^^^^^^^
This _might_ be the problem - some people (foolishly, I think) are
getting picky about matching forward and reverse DNS for HELO.  

steve@hadrian:~$ host diderot.purple.com
Host diderot.purple.com not found: 3(NXDOMAIN)

That might get you a mail deferred, if they're picky about the DNS of
your HELO name.

>       SMTP<< 250-sc006pub.verizon.net
> 	     250-8BITMIME
> 	     250 SIZE 8388608
>       SMTP>> MAIL FROM:<jeff@purple.com> SIZE=5067
>       SMTP<< 450 Requested mail action not taken-Try later:sc006pub.verizon.net
>       SMTP>> QUIT
> 
> I've googled a bit on this problem, it's clearly not unique to me, but
> I haven't seen any solutions posted online.
> 
> I now have one message that has been dropped from the queue and three
> sitting in the queue.
> 
> I suspect this is spam-related, but I'm not clear how to check if I'm
> in any black hole lists (I don't think so, else more would fail) or
> what's going on.  Here's a manual check from krypton.cs.drexel.edu:
> 
>     jeff@krypton:jeff $ telnet relay.verizon.net smtp
>     Trying 206.46.170.12...
>     Connected to relay.gte.net.
>     Escape character is '^]'.
>     220 sc009pub.verizon.net MailPass SMTP server v1.1.1 - 121803235448JY ready Fri, 6 Aug 2004 20:39:37 -0500
>     EHLO krypton.cs.drexel.edu
>     250-sc009pub.verizon.net
>     250-8BITMIME
>     250 SIZE 8388608
>     MAIL FROM:<jeff@purple.com> SIZE=5067
>     450 Requested mail action not taken-Try later:sc009pub.verizon.net
>     rset
>     250 Ok resetting state
>     MAIL FROM:<jeffa@cs.drexel.edu> SIZE=5067
>     250 Sender <jeffa@cs.drexel.edu> OK

ATM it's working again:
steve@hadrian:~$ nc relay.verizon.net 25
220 sc005pub.verizon.net MailPass SMTP server v1.1.1 - 121803235448JY ready Sun, 8 Aug 2004 13:08:40 -0500
ehlo www.lobefin.net
250-sc005pub.verizon.net
250-8BITMIME
250 SIZE 8388608
MAIL FROM:<jeff@purple.com> SIZE=5067
250 Sender <jeff@purple.com> OK
quit
221 sc005pub.verizon.net closing connection

There is a significant pause after mail from:, suggesting that they're
doing a lookup of some sort.

> Any ideas what might be going on or what to do about it?

I think some sort of spam related blocking is going on.  Either they
don't like the DNS of your helo name, and are deferring based on that,
or they're trying to do a 'callout' to check whether the sending address
exists, and that's failing or the lookup is failing, and they're
deferring.  The fact that you got it a second time from another machine
with working DNS suggests that it may be cached.

I see at the moment that your mail is being handled by:
steve@hadrian:~$ host -t mx purple.com
purple.com mail is handled by 10 ftp.ece.villanova.edu.

rather than a purple.com machine.  Was this also the case when things
were failing?  
 
> I just found out today that a different ISP is refusing to *deliver*
> mail to me, no reason given.  *Sigh.*

This sounds kind of significant as well - do you have any error messages
from the DSN's?  This may suggest messed up DNS or something, with \out
knowing any more.
-- 
 --------------------------------------------------------------------------
|  Stephen Gran                  | Advertising is a valuable economic      |
|  steve@lobefin.net             | factor because it is the cheapest way   |
|  http://www.lobefin.net/~steve | of selling goods, particularly if the   |
|  			         | goods are worthless.   -- Sinclair      |
|  			         | Lewis                                   |
 --------------------------------------------------------------------------

Attachment: pgpZuyjJ1UUQG.pgp
Description: PGP signature