[Dovecot] Is it possible to migrating mail to dovecot using imapc?

[Timo Sirainen]

On 30.3.2012, at 22.55, Dr Josef Karthauser wrote:

>> One-way sync will work fine. Two-way sync might be a bit troublesome. For redesigned dsync I've started thinking about kind of a 1,5-way sync. :) That would make sure that all messages from A are copied to B and no messages are deleted from B, but doesn't try to copy new messages from B to A.
>> 
>> http://wiki2.dovecot.org/Migration/Dsync anyway has some docs.
>> 
> 
> But, 'dsync mirror' does a two way sync, doesn't it? Can't I just do that with imapc as the source mailbox?

It does, but the two way sync mirroring relies on messages having GUIDs. IMAP protocol doesn't have such a concept. I guess it could be kind of emulated by using e.g. GUID = sha1(message header). The pop3-replication plugin kind of does this already. But adding such code makes the regular "doveadm backup" slower since now it has to fetch first message headers and then message bodies. But I guess this could be an optional feature. Hmh.