convert mdbox to maildir

[Michael Grimm]

2nd idea (see below)

> On 14. Aug 2022, at 21:15, Michael Grimm <trashcan at ellael.org> wrote:
> 
> lutz.niederer at gmx.net wrote:
> 
>> Yes, you are right.  The problems are not of technical nature.  The reason seems to be some sort of fear (and "admins").
>> We have all we need.  We have the old dovecot config, we have the mdbox files and the complete directory structure.  We are simply not allowed to do all the stuff on the live system.  Even if dsync backup exists that does not modify anything.
> 
> Would they allow a backup to your remote system aka:
> 
> 	doveadm backup -u XYZ -f -d destination
> 
> Have a look at man dovedam-backup for the specifics. Haven't done that before.
> 
> You have to run dovecot at the old server and the new server. The new server has to have maildir set as mail storage. Start with an initial remote backup and incoming mail running at the old server, because that will take some time. At the weekend cut of incoming mail and repeat the backup. Finally you have to redirect mail to the new server. Haven't done that before to a remote server but to different filesystems at one host, instead.
> 
> If I might have misunderstood what you need to achieve, forget about this mail ;-)
> 
> Regards,
> Michael

Or set up replication between old and new server. If all mail is relicated redirect mail to the new server. With this setup they can even continue to use their old server for a while ;-)