Re: [Pan-users] Seeing contents of 'Sent' postings that were never posted

[Duncan]

Maurice posted on Thu, 06 Dec 2018 16:38:30 +0000 as excerpted:

> On Tue, 04 Dec 2018 19:32:34 +0000, I wrote:
> 
>> In my Pan /Local_folders/Sent group I see the Subject line of several
>> postings that never arrived in the target NG.
> 
> 
> Tried again, but:
> 
> "A message that you sent could not be delivered to one or more of its
> recipients. This is a permanent error. The following address(es) failed:
> 
>   address@hidden
>     SMTP error from remote mail server after RCPT
> TO:<address@hidden>:
>     host neru.mageia.org [163.172.148.228]: 450 4.7.25 Client host
> rejected:
>     cannot find your hostname, [195.159.176.226]:
>     retry timeout exceeded"
>     
>  I can't make out what is causing the error.
>  Can *read* from the NG.

OK, that's an understandable, if rather complex, error, related to the 
special situation that is the gmane news server and list2news service.

Keep in mind that gmane is not a normal news server.  Instead, it's a two-
way gateway between the news server it presents to users, and the mailing 
lists that each "group" on the server gateways to.  As such, posting via 
gmane to the list corresponding to a particular group is a much more 
complex dance than is posting to a normal newsgroup, and that dance is 
subject to rather unique errors.

How such posts via gmane normally work:

1) You post via your news client (pan in our case) to the newsgroup on 
the gmane server.  As far as pan is concerned, this is a normal news post.

2) Once gmane gets the message, it checks to see if a post from your 
email address has been posted to the group before, and cleared the gmane-
level email address verification step.  If so, skip to step 5, if not, 
continue with step 3.

3) If your email hasn't been confirmed for that group/list yet, gmane 
sends a confirmation request to the email address you used to post.

4) Gmane waits for a week for confirmation and deletes the message 
without sending it if it gets no confirmation.

5) Assuming gmane address confirmation, either from an earlier message or 
that you confirmed this one, gmane forwards the message to the listserv 
that hosts that mailing list.  At this point, gmane is finished with the 
message unless it gets it back from the listserv either via mail bounce 
if there's an error, or via gmane's list subscription if the message is 
posted to the list.

6) At the listserv, whatever list policies and posting rules the listserv 
and/or specific list in question have get applied.  For some lists this 
means actually posting the message to the list if it's from a subscriber, 
or putting it in a moderator queue for manual approval if not.  Others 
may post messages from unsubscribed addresses, but generally only after 
they pass various antispam tests which may vary from list or listserv to 
list/listserv.  Still other lists, generally announcement lists, etc, are 
mostly read-only, and only certain approved users can post to those lists.

FWIW it's this step, #6, that's the problem in your case.

7) Assuming the listserv actually posts the message to the list, gmane 
gets the message via its list subscription, as it does other messages 
(posted direct to the list, not via gmane), and gateways it to the 
newsgroup.

8) You connect to gmane and download new messages from the newsgroup, 
which will include the ones you posted if and only if the listserv posted 
them to the list, where gmane picked them up in step #7.


It's worth restating here, gmane only posts to the newsgroup messages 
that it gets via its subscription to the list that gateways to that 
newsgroup.  If your message doesn't make it to the list EITHER because it 
failed the gmane email address confirmation step OR because the listserv 
rejected it, reason for the rejection doesn't matter, gmane won't get it 
back via the list, and thus won't post it to the newsgroup.

Thus there are two independent places the message can fail, either the 
gmane email confirmation step (#3), or the list/listserv posting and 
antispam policy step (#6).  This is difficult for a lot of new gmane 
users to understand, and time and again, they'll not realize that there's 
two entirely independent steps here, and will get confused when they've 
setup one but not the other, and the posting fails.


OK, so we've established that the problem is step #6, the list/listserv 
has rejected the message due to its antispam policies.  But what's the 
specific error and how can you fix it?

Of course gmane is munging the specific discuss-* email address due to 
its own antispam measures, so I can't read the specific address, but it 
appears to be a mageia-hosted discussion list of some sort, presumably 
having to do with the mageia distro.  If it comes to it you can put 
spaces in the address so gmane's antispam address munging doesn't trigger 
and we can see the specific list, but I don't think that's necessary in 
this case.

The error...

> cannot find your hostname, [195.159.176.226]: retry timeout exceeded

... indicates that the server tried to do a reverse-dns lookup for the IP 
address 195.159.176.226, which as it happens is gmane's mail and news 
host, see below, and failed to find a DNS hostname entry for that address.

Presumably that's part of whatever antispam policy it has.

And indeed, doing a (reverse) host lookup on that IP address says it's 
not found here either:

$$ host 195.159.176.226
Host 226.176.159.195.in-addr.arpa. not found: 3(NXDOMAIN)

Here's the results for my current IP address to show what it normally 
looks like:

$$ host 24.56.12.188
188.12.56.24.in-addr.arpa domain name pointer 
ip24-56-12-188.ph.ph.cox.net.

(FWIW my ISP is cox.net, with ph.ph indicating that it's in Phoenix and 
the IP address reversed as part of the hostname, tho the city and IP bits 
are cox-specific notation.  It's a standard dynamic IP address.)

Meanwhile, we don't have reverse host name resolution, but who owns the 
IP subnet (excerpt for brevity)?

$$ whois 195.159.176.226
inetnum:        195.159.176.224 - 195.159.176.255
netname:        ROLFOTT-NET
descr:          Rolf Ottesen AS
country:        NO

Norway?  Isn't that where gmane's hosted?  Hmm...

$$ host news.gmane.org
news.gmane.org is an alias for blaine.gmane.org.
blaine.gmane.org has address 195.159.176.226
blaine.gmane.org mail is handled by 5 blaine.gmane.org.

That IP address looks familiar...

So news.gmane.org and blaine.gmane.org are the same IP address, 
195.159.176.226, and mail is handled by the same IP address.

So the mageia listserv is complaining that gmane's mail address doesn't 
have a reverse DNS entry.

Actually, I've seen the same problem for a few other gmane lists.  In 
theory gmane could correct that, but unless/until they do, knowing that 
doesn't help us as mere users...

So what can we as mere users do?

Well, there's a couple possibilities.

1) I'm not sure about mageia's specific policies, but for many lists, 
simply subscribing to the mailing list itself (not the newsgroup!) will 
fix the problem, as they bypass some of the antispam checks for list 
members.  Of course this assumes you're not already doing that.

As far as the subscription, note that most lists have what's called a 
"vacation" or "posting-only" option you can enable after joining, which 
will still allow you to post, but won't send you the emails as it does 
for a normal list.  If you're reading the list via gmane anyway, that's 
quite handy, and I've actually been subscribed to several lists in 
vacation mode for over a decade now...

If there's no posting-only/vacation mode, then look for a digest option.  
This sends you the messages but bundled up in a single big message 
perhaps once a week or once a month (depending on list activity), instead 
of each one individually.  If you like you can then use normal filtering 
on the digest mail to trash it, or just archive it if you want.

2) Most lists have a help option and list master contact address.  Look 
in the list-* headers of messages posted to the individual list/group, or 
check the associated list web site (mageia's lists pages, in this case), 
for details.  You can try contacting the list master and see if they'll 
do a gmane whitelisting exception, or what else they might suggest.

3) Bypass gmane for posting and post via email directly to the list.  You 
can either use pan's email option instead of followup to list, or do a 
followup and then manually copy the contents from the pan window to your 
email client's compose window.  (If pan is setup correctly, it'll 
automatically invoke your email client to send the email anyway, but I've 
noticed that sometimes it only gets part of the message I typed in pan.  
So I'd suggest if you let pan invoke the email client automatically, you 
"send" from pan immediately, and actually compose the reply in the email 
client window it should popup instead of in pan.  That way, there's less 
chance of losing a part of the message you spent all that time composing.)

By bypassing gmane and posting the message directly to the list as if you 
were doing a normal mailing list (not newsgroup) posting, the mail will 
be processed by your email provider, not gmane, and presumably your email 
provider's server has a proper reverse dns entry and thus won't trigger 
that error from the listserv.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman