courier to dovecot migration

[tovises]

>
> On 30.9.2019 12.38, tovises wrote:
>>> On 29.9.2019 23.38, tovises via dovecot wrote:
>>>> I have a quite old home server based on Debian 6.x packages using
>>>> courier
>>>> imap server (exim4, fetchmail, courier, apache2, squirrelmail) to keep
>>>> my
>>>> and my wife emails (about 25G).
>>>> I want renew my server to Debian 10 (buster) and got a recommendation
>>>> to
>>>> use dovecot instead of courier. For this purpose I'm using a different
>>>> PC
>>>> as a sandbox. Debian 10 currently offer dovecot version 2.3.4.1
>>>> Installation was "peaceful" but stuck with the migration. I have
>>>> choose
>>>> migration using dsync, from Wiki I was choose this command:
>>>>
>>>> For per-user user/passwords use:
>>>>
>>>> doveadm -o imapc_user=foo -o pop3c_user=foo -o imapc_password=bar -o
>>>> pop3c_password=bar backup -R -u user at domain imapc:
>>>>
>>>> (foo and bar placed real username and password)
>>>>
>>>> But I get error:
>>>> doveadm(tovis at nusi.tovis-lab.mydomain.org): Error: User doesn't exist
>>>>
>>>> Strongly I have no real domain, I'm using "freedns". "nusi" is the
>>>> local
>>>> name of my old server, "tovis-lab" is conjunction with "mydomain.org"
>>>> choose from freedns. I was trying short as "nusi" which is in
>>>> /etc/hosts
>>>> file even ip address but the same result. 143 and 943 ports are
>>>> working
>>>> only inside the firewall (OpenWrt).
>>>> I was checked using telnet courier on the "remote" box and dovecot on
>>>> the
>>>> localhost. I was able to login.
>>>>
>>>> What should I use as "user at domain" in this situation?
>>>>
>>>>   tovis
>>>>
>>>>
>>>>
>>> Hi!
>>>
>>> -u parameter should be your *local* username, @domain is optional.
>>>
>>> Aki
>>>
>>>
>>>
>> Thank you Aki for quick response!
>> Where i should define the remote IMAP server address/hostname?
>> My localhost run dovecot, remote host (other box) running courier.
>> The user name is the same (password too).
>> -u tovis
>> gives me "Error: Failed to initialize user: Namespace ''; Mailbox list
>> driver imapc: missing imapc_host"
>>
>> Sincerely
>>   tovis
>>
> You can put imapc_host and pop3c_host into config file or provide them
> with -o. If you want to migrate POP3 uidls you need to make sure you
> load that plugin, in either config or providing -o "mail_plugins=list of
> plugins".
>
> Aki
>
>
>
WOW! - amazing quickly, I'm really grateful.

I was using: -u tovis imapc: nusi but still something wrong.
Patstebin: https://pastebin.com/tH4wzJka
The most relevant part (I think) is:
dsync-local(tovis)<rAJmCUTTkV0IBAAAVty4BQ>: Error: read(remote) failed:
EOF (version not received)
doveadm(tovis): Fatal: execvp(imapc:) failed: No such file or directory

What I have missed (doveadm trying to execute something but what).
Any suggestion?

Sincerely
  tovis