Questions about importing mail (mbox)

[Pieter Praet]

On Mon, 21 Mar 2011 19:02:45 -0700, Mueen Nawaz <mueen at nawaz.org> wrote:
> I think you misunderstood me. A part of me suspects this has something
> to do with my not explaining myself, but who's to say?<G>

Same here, apparently :D

> I'm experimenting with notmuch, and if I can translate everything I
> currently do in mutt to notmuch, then I'll just dump mutt. The set of
> mboxes I have will remain archived, but for all future incoming email,
> I'll switch to MH or MailDir. So I don't actually need to put my old
> mboxes under revision control - I just need to save them somewhere.

I strongly agree that long term storage choices are a matter of personal
opinion, however the intention of my proposition was to simply keep
track of what changed in the mbox as a result of the various ops
performed, as to gain insight in what gets messed up and where.

Non-VCS would be something along the lines of:
    compact mbox.orig > mbox.comp   # (*if* "compact" were a valid command)
    diff mbox.orig mbox.comp
    mb2md -s ./mbox.comp -d ./maildir
    cat ./maildir/new/* >> mbox.conv
    diff mbox.comp mbox.conv

> > For the actual conversion to Maildir (and any type of mail fetching in
> > general), I'd suggest using FDM [2], you'll never look back.
> 
> Thanks - will take a look.
> 
> > Regarding the significant discrepancy between processed and added files
> > in Notmuch: Could be dupes (e.g. mail to/cc/bcc yourself or mailing
> > lists, ending up in both Inbox and Sent), which are automatically
> > suppressed by Notmuch.
> 
> It definitely was dupes. I didn't realize that notmuch did not keep
> track of dupes. 
> 
> So I wrote a Python script to go through the mboxes and do a count of
> only unique messages. Problem? I have over 1000 emails that don't have a
> Message-ID header (case invariant search). I could go over why that is,
> but suffice it to say that I hate Microsoft.<G>
> 
> Once I remove all dupes, I get to within 300-400 of the count that
> notmuch provides. The remaining 1000+ emails do contain some dupes, and
> I can't find a convenient way to get an accurate count of unique emails
> from them, but at least now I'm in the ballpark, and a lot more
> confident.

Sadly, both mb2md and fdm *will* mess things up, since they both split
on every single occurence of "^From " [1,2], even if it isn't a
separator line.

Both assume occurences of "^From " in the message body to be already
escaped like so: "^>From " [3,4].

Even worse, RFC 4155 [5] confirms this to be semi-expected behaviour:
>> Many implementations are also known to escape message body lines that
>> begin with the character sequence of "From ", so as to prevent
>> confusion with overly-liberal parsers that do not search for full
>> separator lines.  In the common case, a leading Greater-Than symbol
>> (0x3E) is used for this purpose (with "From " becoming ">From ").
>> However, other implementations are known not to escape such lines
>> unless they are immediately preceded by a blank line or if they also
>> appear to contain an email address and a timestamp.  Other
>> implementations are also known to perform secondary escapes against
>> these lines if they are already escaped or quoted, while others
>> ignore these mechanisms altogether.

One way to circumvent this is by making use of the Content-Length header
(which is apparently how Mutt does it [6]), but guess what, it suffers
the same fate as Message-ID...

> Incidentally, one reason I didn't realize dupes were the reason is that
> I did a search for a word in one email I had and notmuch did not find
> it - so I assumed it had not been indexed. Later on, I realized I had
> written a partial word and discovered that notmuch does find it if I
> type the full word.
> 
> What am I doing wrong? Can't notmuch handle partial word matches? Do I
> need to specify an option to get that to work?

AFAIK, this depends on how Xapian splits terms, so isn't a Notmuch issue.
Globbing helps (sometimes).

query: "partia AND from:mueen at nawaz.org"
    returns nil

query: "partia* AND from:mueen at nawaz.org"
    correctly returns this thread.



Peace

-Pieter


[1] mb2md, line 999 (http://www.linuxkungfu.org/files/scripts/mb2md)
[2] fdm, line 461 (http://fdm.cvs.sourceforge.net/viewvc/fdm/fdm/fetch-mbox.c?view=markup)
[3] mb2md, line 1342 (http://www.linuxkungfu.org/files/scripts/mb2md)
[4] fdm, line 468 (http://fdm.cvs.sourceforge.net/viewvc/fdm/fdm/fetch-mbox.c?view=markup)
[5] RFC 4155, section 2, paragraph 5 (http://tools.ietf.org/html/rfc4155)
[6] http://www.mail-archive.com/mutt-users@mutt.org/msg21921.html