dovecot - Nov 2009 - Migrating existing local Maildir structure to dovecot server Maildir

Hello,

I'm about to migrate a number of existing users who have been using
POP3 with emails stored locally in KMail's Maildir format into an IMAP
solution based on Dovecot.

Will it be possible to simply move all the KDE Maildir folders from
the local PCs to the Maildir folder on the IMAP server running Dovecot
and then have the emails accessible on the server, or will this most
likely mess up the Dovecot index files?

If this causes index file trouble, is there any way to force a
re-indexing of all these files, or is there another recommended way of
migrating up to 7 years of email communication from local hosts to the
IMAP server, for later putting them in folders?

Thanks in advance!

(PS. I noticed a few of the howto's on how to migrate to dovecot, but
they only focus on moving from mbox to dovecot or similar, and not
migrating existing Maildir emails to a new dovecot server... Any such
pointers would be greatly appreciated :-))

 -y1

On Friday 13 November 2009 15:00:09 Halim Issa wrote:
> Hello,
>
> I'm about to migrate a number of existing users who have been using
> POP3 with emails stored locally in KMail's Maildir format into an
> IMAP solution based on Dovecot.
>
> Will it be possible to simply move all the KDE Maildir folders from
> the local PCs to the Maildir folder on the IMAP server running
> Dovecot and then have the emails accessible on the server, or will
> this most likely mess up the Dovecot index files?
>
> If this causes index file trouble, is there any way to force a
> re-indexing of all these files, or is there another recommended way
> of migrating up to 7 years of email communication from local hosts to
> the IMAP server, for later putting them in folders?
I don't think the migration of the Maildir structure itself is the 
problem. Dovecot has no problem reading it, no matter where it came 
from, as long as it is a proper Maildir structure. Existing indexes 
should not be affected.

The indexes that KMail writes, however, will probably not migrate well 
or at all. I do not know anything about the index format KMail uses but 
converting it to something Dovecot understands and accepts seems 
troublesome and difficult to me.

This means that you can copy all existing, local Maildirs over to the 
server (you can even put them in subfolders in existing accounts) and 
Dovecot will read them just fine. But it also means that Dovecot will 
very probably present them to the user as new messages, never seen 
before. 

But do yourself a favour and test any procedure you plan on implementing 
properly and extensively before actually implementing it. Otherwise it 
could end up messy and irreparable.

HTH

Andreas
-- 
Andreas Ntaflos
Vienna, Austria

GPG Fingerprint: 6234 2E8E 5C81 C6CB E5EC  7E65 397C E2A8 090C A9B4
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On 16/11/2009, Andreas Ntaflos <daff at dword.org>
wrote:
> On Friday 13 November 2009 15:00:09 Halim Issa wrote:
>> Hello,
>>
>> I'm about to migrate a number of existing users who have been using
>> POP3 with emails stored locally in KMail's Maildir format into an
>> IMAP solution based on Dovecot.
>>
>> Will it be possible to simply move all the KDE Maildir folders from
>> the local PCs to the Maildir folder on the IMAP server running
>> Dovecot and then have the emails accessible on the server, or will
>> this most likely mess up the Dovecot index files?
>>
>> If this causes index file trouble, is there any way to force a
>> re-indexing of all these files, or is there another recommended way
>> of migrating up to 7 years of email communication from local hosts to
>> the IMAP server, for later putting them in folders?
>
> I don't think the migration of the Maildir structure itself is the
> problem. Dovecot has no problem reading it, no matter where it came
> from, as long as it is a proper Maildir structure. Existing indexes
> should not be affected.
>
> The indexes that KMail writes, however, will probably not migrate well
> or at all. I do not know anything about the index format KMail uses but
> converting it to something Dovecot understands and accepts seems
> troublesome and difficult to me.
>
> This means that you can copy all existing, local Maildirs over to the
> server (you can even put them in subfolders in existing accounts) and
> Dovecot will read them just fine. But it also means that Dovecot will
> very probably present them to the user as new messages, never seen
> before.
>
> But do yourself a favour and test any procedure you plan on implementing
> properly and extensively before actually implementing it. Otherwise it
> could end up messy and irreparable.
Thanks much for your thorough answer! I'll make sure to test extensively.

One thing came to mind - would it be possible to use Dovecot and
Disconnected IMAP itself for the transfer, and perhaps thus keep the
indexes?
If I move the messages from the local mailbox to the IMAP mailbox from
within Kmail it should perhaps keep the status?

Also - is there any documentation anywhere (or tips on better google
search terms) on what is stored in these indexes? I suppose apart from
Read/New status, it also contains whether or not there have been
replies to the mail and on what date the email was replied to?

Thanks again!