Hello,

Sorry for the reply delay, I had to worry about something else …

Here is my doveconf -n:

# 2.3.4.1 (f79e8e7e4): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.4 ()
# OS: Linux 4.19.0-6-amd64 x86_64 Debian 10.4
# Hostname: [my-host-name]
auth_debug = yes
auth_debug_passwords = yes
auth_verbose = yes
auth_verbose_passwords = yes
imapc_features = rfc822.size fetch-headers
imapc_host = [remote-imap-host]
imapc_password = # hidden, use -P to show it
imapc_user = [my-remote-user-name]@[with-domain]
log_path = /var/log/dovecot.log
mail_debug = yes
mail_location = mbox:~/mail:INBOX=/var/mail/%u
mail_prefetch_count = 20
mail_privileged_group = mail
namespace compat1 {
  alias_for =
  hidden = yes
  list = no
  location =
  prefix = mail/
  separator = /
}
namespace compat2 {
  alias_for =
  hidden = yes
  list = no
  location =
  prefix = Mail/
  separator = /
}
namespace inbox {
  inbox = yes
  location =
  mailbox "&AMk-l&AOk-ments envoy&AOk-s" {
    special_use = \Sent
  }
  mailbox "&AMk-l&AOk-ments supprim&AOk-s" {
    special_use = \Trash
  }
  mailbox Brouillons {
    special_use = \Drafts
  }
  mailbox "Courrier ind&AOk-sirable" {
    special_use = \Junk
  }
  prefix =
}
passdb {
  driver = pam
}
passdb {
  args = scheme=MD5-CRYPT username_format=%u /etc/dovecot/users
  driver = passwd-file
}
plugin {
  sieve = file:~/sieve;active=~/.dovecot.sieve
}

ssl_ca = </etc/letsencrypt/live/default/chain.pem
ssl_cert = </etc/letsencrypt/live/default/cert.pem
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
userdb {
  driver = passwd
}
userdb {
  args = username_format=%u /etc/dovecot/users
  driver = passwd-file
}

There is certainly something trivial there, but I'm not very used to advanced usage of Dovecot.

Regards,

Le 08/06/2020 à 10:32, Sami Ketola a écrit :

On 7. Jun 2020, at 16.13, Gingko <ldiff001@gingko.ovh> wrote:

Hello,

I also have issues using Dovecot Backup.

I am trying to Backup (or possibly Sync - one way) a single user IMAP account from a remote server, unknown type, to my own server.

For that purpose, I defined the following parameters :

imapc_host = <host name>
imapc_user =<user name>
imapc_password = <password>
imapc_features = rfc822.size

(<user name> has format: name@example.com, and <host name> is the name of the imap remote server that I use for getting mails)

… and then  I issued the following command:

doveadm backup -R -u <user name, format name@example.com> imapc:

... but doing this, I get the following answer:

dsync(<user name>): Info: imapc(<host name>:143): Connected to <host IP address>:143 (local 192.168.1.2:52940)
dsync(<user name>): Error: Failed to initialize user: namespace configuration error: Namespace mail/ can't have alias_for= to a different storage (different root dirs)

How can I solve this?

If there is something not matching between servers, I may eventually change configuration on my side, but I think I would first have to know which feature(s) I have to know from the remote server in order to create the matching one on my server.

Is there a way to list all relevant data coming from the remote server?

Also:

Doing this, is it necessary that the source user name be the same as the destination user name? Is it possible to backup an IMAP account to a user account having a completely different name?

Nope. Source and destination usernames can be different. Please post your doveconf -n as this is probably an error on your local config.

Sami