====== Mirgrating courier ========

migrating whole Courier soulutions means basicly migrating only imap and maildrop deliverer. The rest pop3 and auth daemon are trivial.

===== Case Study =====
Original virtual maildir structure ''/var/mail/virtual/example.com/name.surname/Maildir'' has additional special path ''/Maildir'' at the end. New should map to ''/srv/mail/virtual/example.com/name.surname/Maildir''

**First Solution** for simple cases is simple. In simple case all your e-mails user@domain match the structure above (''/path/domain/user'') and ''maildir'' column in your database is funny overhead. Add to your ''dovecot.conf''

<file>
auth default {
  ...
  userdb static {
      args = uid=1001 gid=1001 home=/srv/mail/virtual/%d/%n allow_all_users=yes
  }
  ...
}
mail_location = maildir:~/Maildir
</file>

**Second Solution** is to change the sql query int dovecot-sql.conf
<file>
user_query = SELECT maildir as home, uid, gid, concat('maildir:', maildir, '/Maildir') as mail FROM mailbox WHERE username = '%u'
</file>
and set up different userdb source in dovecot.conf
<file>
auth default {
  ...
  userdb sql {
    args = /etc/dovecot/dovecot-sql.conf
  }
  ...
}
</file>
forget the mail_location.

===== Theory Behind =====
Is that realy a theory? It is the code behind. Final deliverer LDA is ''deliver''. It is given one parameter ''-d {recipient'' which is ''-d name.username@example.com''. First it asks dovecot auth socket for additional data like uid, gid, maildir path. 

===== Syncing Dirs =====
at source host:
  for i in /var/mail/virtual/*/; do echo $i; rsync -a  --rsh='ssh -c blowfish' $i wd@81.0.212.153:$i; done

at new host:
  ./courier2dovecot.pl --to-dovecot --convert --recursive /var/mail/virtual/*