UW-IMAP ======= *WARNING: Badly done migration will cause your IMAP and/or POP3 clients to re-download all mails. Read 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 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 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 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 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. * 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 2019-06-19 12:42)