Re: [exim] Working with Exim queue metadata (was: View attachments inqueue?)

Szerző: Ian Eiloart
Dátum:
Címzett: Kerwin@HIMAP
CC: exim users
Tárgy: Re: [exim] Working with Exim queue metadata (was: View attachments inqueue?)

--On Wednesday, September 22, 2004 6:55 pm +0800 "Kerwin@HIMAP"
<kerwin@???> wrote:

> What if it has no sender there?what does it mean?when only <>is present...

Its a bounce message, or a vacation message, or some other automatically
generated reply.

> ----- Original Message -----
> From: "Peter Savitch" <x765y@???>
> To: "Eric" <exim@???>
> Cc: <exim-users@???>
> Sent: Wednesday, September 22, 2004 6:27 PM
> Subject: [exim] Working with Exim queue metadata (was: View attachments
> inqueue?)
>
>
> I hope list users will forgive me. Not everybody know that Exim is almost
> incapable of MIME multipart handling (at least, Exim does not have
> intrinsic 100% MIME conformance because it's MTA, not MUA). If reader
> concerned on MIME handling and control policy, then just exiscan,
> http://duncanthrax.net/exiscan-acl/.
>
> Reader of this memo should be familiar with MIME.
>
> So, tÓ view the attachments in the queue, one can:
>
> 1) Find the message in Exim's queue using -bp option:
>
># exim -bp
>
> 0m 259 1CA3To-0001vO-2P <somebody@???> > otherbody@???

>
> 1*) If you do not want Exim to deliver the message while you investigating
> it, then freeze it manually with -Mf option (you can always thaw the
> message back with -Mt):
>
># exim -Mf 1CA3To-0001vO-2P
> Message 1CA3To-0001vO-2P is now frozen
>
># exim -bp > 24m 12K 1CA3ad-0001w1-J6 <somebody@???> *** frozen *** > otherbody@???

>
> 2) Examine the metadata and MIME contents of the message in the queue,
> using message's internal Exim id (do not mess with the Message-Id header,
> this usually different than Exim's). Use -Mvh option:
>
># exim -Mvh 1CA3ad-0001w1-J6
>
> ... > 128P Received: from root by relay.domain.org with local-smtp > id 1CA3ad-0001w1-J6 > for otherbody@???; Wed, 22 Sep 2004 13:32:16 +0400 > 014 Subject: TEST > 047I Message-Id: <1CA3ad-0001w1-J6@???> > 026F From: somebody@??? > 038 Date: Wed, 22 Sep 2004 13:32:12 +0400 > 018 MIME-Version: 1.0 > 081 Content-Type: multipart/mixed; > boundary="----_=_NextPart_001_01C4A085.E3E1FF30" > 028T To: otherbody@???

>
> One could note the `I', `F' and `T' letters that obviously marks the
> appropriate headers (Message-Id, From and To). These things are described
> well in specs, chapter 49, Format of spool files, and can be used by
> custom software that examines Exim's spool zone (queue).
>
> 3) Extract the message body from the queue. Like the latter one, but -Mvb:
>
># exim -Mvb 1CA3ad-0001w1-J6
>
> 1CA3ad-0001w1-J6-D
> This is a multi-part message in MIME format.
>
> ------_=_NextPart_001_01C4A085.E3E1FF30 > Content-Type: multipart/alternative; > boundary="----_=_NextPart_002_01C4A085.E3E1FF30"

>
>
> ------_=_NextPart_002_01C4A085.E3E1FF30 > Content-Type: text/plain; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable

>
> [snip]
>
> ------_=_NextPart_001_01C4A085.E3E1FF30 > Content-Type: image/jpeg; > name="5019.jpg" > Content-Transfer-Encoding: base64 > Content-Description: 5019.jpg > Content-Disposition: attachment; > filename="5019.jpg"

>
> /9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHVja3kAAQAEAAAAPAAA/+4AJkFkb2JlAGTAAAAAA
> QMA
> FQQDBgoNAAAI1QAAC6QAABLHAAAcyP/bAIQABgQEBAUEBgUFBgkGBQYJCwgGBggLDAoKCwoKD
> BAM
> DAwMDAwQDA4PEA8ODBMTFBQTExwbGxscHx8fHx8fHx8fHwEHBwcNDA0YEBAYGhURFRofHx8fH
> x8f [...]
>
> As you can see, the first line is the message id, followed by MIME
> entities, that is, the message body. If you are interested in images,
> find the string `Content-Type: image/'. Then, skip the MIME part headers,
> take the base64-encoded image (with text editor) and blow it to mimencode
> -u:
>
># cat encoded.txt | mimencode -u -o image.jpg
>
> Exact file extension can be looked up in the part headers, by
> content-type, or by filename parameter. Looks ugly, some automated things
> could be done, but if you want to control ALL images, you are going to
> use spam scanning tools. It's not possible to do such things by hand. BTW
> porn images are caught well by special spectral analysis, because human
> skin color spectral curves are known a priori ;-)
>
> 4) Okay, when you are done with the message, you should decide what to do
> next: either to deliver it in a normal way or drop (remove from the
> queue). In the latter case, you can choose between kicking it off
> silently or giving the bounce to the sender.
>
> To simply thaw (release, opposite to -Mf option) the message and give it
> back to the SMTP world:
># exim -Mt 1CA3To-0001vO-2P
>
> To kick off the message silently (-Mrm sounds like POSIX `rm' command):
># exim -Mrm 1CA3To-0001vO-2P
>
> To give up and bounce (simulate permanent delivery failure):
># exim -Mg 1CA3To-0001vO-2P
>
> To skip the delivery to address otherbody@???:
># exim -Mmd 1CA3To-0001vO-2P otherbody@???
>
> And, to change the envelope sender:
># exim -Mes 1CA3To-0001vO-2P othersender@???
>
> 5) And for now, some advanced things. If you've got an urgent condition
> and need to wipe the queue in emergency then use tools like awk, sed,
> grep, etc combined with Exim's -bp and -Mrm options. One could do the
> things like:
>
> exim -bpr \
> | fgrep '<somebody@???>' \
> | awk '{ print $3; }' \
> | xargs -n 32 exim -Mrm
>
> In this sample, we get the ids of messages sent by somebody@???
> (note brackets!) and ask Exim to remove them, splitting by chunks of 32.
> You can of course use -Mf option instead of -Mrm to just freeze the
> messages for further investigation.
>
> PS
> Though this memo copies the manual, it gives the way of sample using
> Exim's options not everybody knows but yet useful. Especially with large
> queues ;-)
>
> --
>## List details at http://www.exim.org/mailman/listinfo/exim-users Exim
> details at http://www.exim.org/ ##

--
Ian Eiloart
Servers Team
Sussex University ITS

Re: [exim] Working with Exim queue metadata (was: View attac…