Horn Wijaya wrote:
TESTED AND RUNNING, MIGRATING from MBOX to MAILDIR, PRESERVE UID and OUTLOOK
- mb2md-3.20.pl -s /var/mail/hwijaya -d home/hwijaya/Maildir/ that's converting 444 emails from mbox to 444 files in the Maildir/cur folder
- cd /home/hwijaya/Maildir/cur
- grep IMAPbase * and I get 1210219860.000000.mbox:2,S:X-IMAPbase: 1202794557 19944 The last 2 strings are the KEY to the ORIGINAL UID
- So in order to prepare the environment to fool it, some calculations are needed: How do we get 19501 as the first counter? as expected in the first POP TEST above: 19944 - 444 emails + 1 = 19501
- cd /home/hwijaya/Maildir
- echo '3 V1202794557 N19501' > dovecot-uidlist
Hello,
First of all, I was looking into this problem of getting the right converter for couple years. You can search list archives for that - there are more problems with perfect migration, than you know of. Second, your calculations assume two things, that are not always true - puts these headers)
- original mailbox already has X-IMAPbase header (not every mail server
- first message UID is last message UID-<number of messages>, which is not true, if you have deleted some messages in between. Third, usually servers use different UIDL format, not time+number. Last, if you are migrating from mbox to Maildir on IMAP server, then you have more than one folder. Probably you have "/" as folder separator on mbox-based system. And will have "." on Maildir. That means, Outlook will need to refresh it's folder list anyway. And that involves re-downloading all messages.
Yes, in your case you might be able to make a perfect migration tool, but this won't be ideal for everybody.
P.S. After couple years of thinking, planning and looking for a ideal solution I have modified mb2md-3.20.pl script a little and was able to migrate about 200Gb of mail with no problem. Yes, most clients had to re-download all their messages (I had to force POP3 clients to empty their server mailboxes), but it wasn't that big of a deal, as I was afraid of. And now, even with much slower hardware I see about 10 times lower LA than with mbox.
FiL