Re: [Exim] Question regarding migration to exim

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Author: Tor Slettnes
Date:  
To: Chris J. Babyak
CC: exim-users
Subject: Re: [Exim] Question regarding migration to exim
On Mar 23, 2004, at 07:40, Chris J. Babyak wrote:
> Our old system was qmail and maildir mailstores. The new exim box has
> been setup with mbox mailstores.


Why? The Maildir format is slow, but mbox format is even slower.
Plus, it has other problems associated with it, such as the need to
escape lines that start with the word "From ".

I presume your users also access their mail through IMAP or POP-3? If
so, you would also have to change your IMAP/POP3 server software
(probably from Courier to something like UW-IMAPd or DoveCot).

I would instead keep your mail in "Maildir" spools. Exim has built-in
Maildir support. In the default configuration (at least on my Debian
box), there is a "maildir_home" transport defined. Simply set
LOCAL_DELIVERY=maildir_home.

Or, if you want something with higher performance, migrate to the Cyrus
suite of tools: Deliver mail via LMTP, read them via IMAP (preferrably)
or POP-3.


> Some of the users have already been migrated with old mailstores still
> sitting on the qmail box.


Too bad. I would still have these migrate back.


> What kind of migration technique would be the best for moving this old
> mail? There's always drag/drop which is effective enough for a few
> users, but not for more than 5 or 10. Mailstores could be converted
> from maildir to mbox with qmail's maildir2mbox utility and then the
> newly created inbox file transferred -this seems to work OK if the
> user hasn't been already using the new box. But for the user who has
> new mail already on the new box and needs their old mail, is just
> appending the old mail (converted maildir2mbox file) to the new inbox
> file OK? Or does that present problems for the way mbox format files
> are read.


I would try it out:
     cp /var/mail/someuser /var/mail/someuser.backup
     maildir2mbox <....>


And if everything looks OK:
     rm /var/mail/someuser.backup




> Popping the old mail over to the new box via SquirrelMail's mail_fetch
> utility might work out, but I believe there's an issue with having
> dates on the mail carried across.


Correct me if I am wrong, but does not SquirrelMail use IMAP to access
your mail? As such, that would be a function of the interaction
between your IMAP client (squirrelmail) and your IMAP server.

-tor