[Dovecot] dovecot with IMAP and POP3 mixed

[Bill Cole]

Andreas Meyer wrote, On 3/21/09 11:16 AM:
> Hello!
>
> I tried to setup dovecot to work with IMAP and POP3 but when I connect
> with Squirrelmail, I get an error saying CREATE "INBOX.Sent"
> reason: Mailbox doesn't allow inferior mailboxes

That's for user7, right?

The cause of that error is SquirrelMail (using IMAP) is trying to create a 
mailbox as a child of INBOX, but since user7 is defined as using mbox 
format, that fails. If you use mbox storage, an IMAP folder can have either 
messages or subfolders but never both, because when using mbox an IMAP 
folder containing messages is a file, while an IMAP folder containing 
subfolders is a directory. See http://wiki.dovecot.org/MailboxFormat/mbox 
for more info.

There *should* be some way to make SquirrelMail stop trying to create its 
folders under INBOX, but I have no idea if there actually *is* one. Some 
IMAP servers only allow the creation of folders as children of INBOX, and as 
a result some (broken) IMAP clients only know how to create folders that 
way. You can accommodate such software in Dovecot by using namespaces.

I think you should start by reading http://wiki.dovecot.org/MailLocation and 
http://wiki.dovecot.org/Namespaces to understand your options.


> # dovecot --version
> 1.0.5
>
> # dovecot -n
> # 1.0.5: /etc/dovecot/dovecot.conf
> log_path: /var/log/dovecot
> protocols: imap imaps pop3
> ssl_disable: yes
> login_dir: /var/run/dovecot/login
> login_executable(default): /usr/lib/dovecot/imap-login
> login_executable(imap): /usr/lib/dovecot/imap-login
> login_executable(pop3): /usr/lib/dovecot/pop3-login
> mail_location: maildir:/var/spool/vhosts/%d/%n
> mail_executable(default): /usr/lib/dovecot/imap
> mail_executable(imap): /usr/lib/dovecot/imap
> mail_executable(pop3): /usr/lib/dovecot/pop3
> mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
> mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
> mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3
> pop3_uidl_format(default):
> pop3_uidl_format(imap):
> pop3_uidl_format(pop3): %08Xu%08Xv
> auth default:
>    passdb:
>      driver: passwd-file
>      args: /etc/dovecot/passwd
>    userdb:
>      driver: passwd-file
>      args: /etc/dovecot/passwd
>
> and /etc/dovecot/passwd looks like this:
>
> anmeyer at anup.de:{PLAIN}password:5000:5000::/var/spool/vhosts/anup.de/anmeyer::userdb_mail=maildir:~/
> user7 at anup.de:{PLAIN}password7:5000:5000::/var/spool/vhosts/anup.de/user7::userdb_mail=mbox:~/:INBOX=/var/spool/vhosts/anup.de/%u
>
> The mbox of user7 already exists. Can someone help to get both variants working
> so that dovecot can handle IMAP and POP3 accounts?

This is not about POP3 and IMAP, it is about storage formats. POP3 and IMAP 
are both able to use either maildir or mbox storage. Users are not 
restricted to one or the other access protocol, no matter what storage 
format they use.