

UW-IMAP
=======




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<< for an example configuration. 
 3. Configure Dovecot to use home directory ('mail_location = mbox:~/:INBOX=/var/mail/%u' and set '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<< 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<< script to copy all the users' '.mailboxlist' files to '.subscription' 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<< 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<< has some migration scripts 


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
---%<-------------------------------------------------------------------------

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 2007-12-11 04:42)
