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?