Re: using movemail directly in .emacs

[Robert Thorpe]

lee <lee@yun.yagibdah.de> writes:
> The anachronism is storing many emails in one file.
>
> That was done in the past because file systems were used the performance
> of which would be severely impacted when you had many files in the same
> directory.  Without this limitation, it doesn`t make sense to put many
> emails into a single file, even if it`s only 10 or 5, other than for
> special purposes.  It is a bad idea to do that because the single file
> is prone to locking problems and corruption, and it can easily become
> unwieldy and very slow to work with.  Using a number of single files
> ("folders") doesn`t really make it better.
>
> IIRC, maildir supports flags (like read, answered) in the file names,
> with, besides efficiency, the advantage that every MUA which supports
> maildir can understand the flags.  When you use mbox, you either have to
> use some sort of index file to store the flags, or you need to re-write
> the whole file when a flag changes, and each MUA may use their own way
> for this, not understood by others.  How efficient is that?
>
> Using mbox is as much an anachronism as using a spool file for storing
> email:  It`s still a single file.

I agree that storing gigabytes of email in a single file is unwise.
Keeping it in the spool file of a multi-user installation is a even
worse since some sysadmins delete spool files that are too large.

In general though storing lots of emails in a file isn't really a
problem.  I've used email clients that do that for many years and I
haven't had any problems.  I have gigabytes of mail in mbox files, but
it's not all in one file.  I file things and I that keeps the largest
file smaller than ~150MB, most are much smaller.  I don't have a very
fast computer, I bought it four years ago, but even so the delay in
writing out files isn't very noticable.  That's because when the program
writes the file out it goes into the disk cache first and it's only
written to hard drive later on.  I use Rmail at present, though I have
used other MUAs.  Rmail saves a backup file for every mbox file.  Even
so I've never had a problem with corruption, using Rmail or any other
program.  Mbox files are very simple, it's hard to get writing to them
wrong.

You're right about flags though.  Mbox files aren't very portable
between mailers for that reason.  Another, bigger, problem is coding
systems.  Thunderbird (for example) treats mbox files as ASCII [1].  If
you get a UTF-8 email in Thunderbird then it inserts it as base64 (well
I assume it's base64) into the mbox.  On the other hand in Rmail seems to
inserts it as UTF-8.  Both work correctly but in their own way.

I'm not saying that it's best to use mbox files, but the problems with
them aren't large.  Large directory structures have other problems.

[1] - I think it's ASCII, it may be Latin-1 or something.

BR,
Robert Thorpe