Edit File: Migration.UW.txt
UW-IMAP ======= *WARNING: Badly done migration will cause your IMAP and/or POP3 clients to re-download all mails. Read <Migration.txt> page first carefully.* Namespaces ---------- By default UW-IMAP allows access to whole home directory. Since the home directory may contain many other files as well, many people have chosen to store their mails in the 'mail/' directory. This usually means that IMAP clients have been configured to use 'mail/' as their "IMAP namespace prefix" (the clients use different names for this). This doesn't work with Dovecot, because Dovecot shows clients only the 'mail/' directory instead of the whole home directory. So if the IMAP namespace was kept as 'mail/', Dovecot would try to access the '~/mail/mail/' directory. There are three ways to fix this: 1. Remove the IMAP namespace prefix from the clients. 2. Use namespaces to allow users to keep using the prefix. See "Backwards Compatibility" in <Namespaces.txt> for an example configuration. 3. Configure Dovecot to use home directory ('mail_location = mbox:~/:INBOX=/var/mail/%u' and set 'mail_full_filesystem_access=yes'). The latter is needed to make '~/mail' and '~user/mail' prefixes work. A typical mailbox location setting is: ---%<------------------------------------------------------------------------- mail_location = mbox:~/mail:INBOX=/var/mail/%u ---%<------------------------------------------------------------------------- ~/mbox file ----------- If a '~/mbox' file exists, UW-IMAP moves all the mails from '/var/mail/user' into the '~/mbox' file. Currently Dovecot doesn't support this feature. There are two possibilities to handle this: * Move everyone's mails to '~/mbox' and reconfigure your <MDA.txt> to deliver new mails there by default. * Move the existing mails from '~/mbox' back to '/var/mail/user'. Subscriptions ------------- UW-IMAP keeps the list of subscribed mailboxes in '~/.mailboxlist' file, while Dovecot keeps them in '~/mail/.subscriptions' file. UW-IMAP's subscriptions also contain the mailboxes with their prefixes, for example: ---%<------------------------------------------------------------------------- mail/box ~/mail/box2 ~user/mail/box3 ---%<------------------------------------------------------------------------- * If you removed the prefix from the IMAP clients, you'll also have to remove these prefixes. * You can use <uw2dovecot.sh.txt> script to copy all the users' '.mailboxlist' files to '.subscriptions' files (without any prefix removal). * It's possible to keep using the '.mailboxlist' filename (as long as it's in the same directory) by modifying 'SUBSCRIPTION_FILE_NAME' define in 'src/lib-storage/index/mbox/mbox-storage.h' UIDs, flags and keywords ------------------------ Dovecot uses UW-IMAP compatible metadata headers in mboxes, so it's possible to migrate back and forth without losing any flags, keywords or cause IMAP UIDs to change. Locking ------- UW-IMAP uses dotlock + flock() as the default locking combination, while Dovecot uses dotlock + fcntl() by default. See <MboxLocking.txt> to determine what are the correct lock settings for you. To use UW-IMAP compatible locking, use: ---%<------------------------------------------------------------------------- mbox_read_locks = flock mbox_write_locks = dotlock flock ---%<------------------------------------------------------------------------- DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA ------------------------------------------------- The first message in a mbox file may contain the subject "DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA". This system message has information about the mailbox and its state. Dovecot v1.0 uses these system messages. Keep them. Maildir conversion ------------------ If you're planning on migrating to Dovecot, you might also want to switch to Maildir format as well. However it might be easier to first migrate from UW-IMAP + mbox to Dovecot + mbox, and only then migrate the users to Maildir format. * http://people.redhat.com/rkeech/maildir-migration.txt describes how to migrate from UW-IMAP+mbox to Dovecot v0.99 + Maildir. Note that Dovecot v0.99 has slightly different configuration file settings. * <Migration.MailFormat.txt> has some migration scripts * Here is a tool ([attachment:uw2dovecot.pl]) that will convert mbox, mbx, and mix formatted UW-IMAP folders to Maildir/dovecot format. UW-POP3 (UW-IMAP's POP3 wrapper, ipop3d) ======================================== By default Dovecot generates POP3 UIDLs differently than UW-POP3, which causes POP3 clients to redownload them as new messages. You can avoid this by setting: ---%<------------------------------------------------------------------------- pop3_uidl_format = %08Xv%08Xu ---%<------------------------------------------------------------------------- To utilize the UW login conversion to lowecase, we recommend that you use the following option: ---%<------------------------------------------------------------------------- auth_username_format = %Lu ---%<------------------------------------------------------------------------- You can confirm that the old and the new UIDLs match: ---%<------------------------------------------------------------------------- telnet localhost 110 user test pass test uidl quit ---%<------------------------------------------------------------------------- (This file was created from the wiki on 2018-02-28 04:42)