I would like to transfer mail for some users from an old dovecot (with no doveadm) to a modern dovecot (2.3.2). I've read up on https://wiki2.dovecot.org/Tools/Doveadm/Sync https://wiki2.dovecot.org/Migration/Dsync

and I'm not sure if I can use doveadm for this purpose.

I need doveadm to login to the remote server (source) with a username/password via IMAP, fetch all mail and deliver it to a local user (target), preferrably with the same folder structure that exists on the source account. Is this possible?

I don't understand this page completely: https://wiki2.dovecot.org/Migration/Dsync

For some testing (that's why I used pop3, to keep it simple) I put a file for pop3c in conf.d (mostly identical with the file shown on that page) and restarted dovecot. Then I tried a command line like this: doveadm -o pop3c_user=user -o pop3c_password=password backup -R -u user@domain pop3c: This creates an error: dsync(user@domain): Error: Mail locations must use the same virtual mailbox hierarchy separator (specify separator for the default namespace)

I'm not sure what this exactly means. Does it refer to the account naming structure of user@domain? The source server does not have such usernames, only the target server I run the command on. Or does it refer to structure within the mailbox? (which can't really be the case as it doesn't login to the source and can't know the structure yet). So, if it indeed refers to the user naming structure, can I tell it to use the "simple" account names on the source machine?

Am I correct in assuming that I can override any pop3c_ setting in the conf file with -o? For instance also using -o pop3c_host= and that if there is -o pop3c_user=user on the command line I don't need a pop3c_user in the conf file? (no master-user).

Thanks for any help on this. (If it doesn't work I can use fetchmail, but that is much less preferrable as it "delivers" all mail, so it's all "new" and in the INBOX.

Kai