Update: seems to me that the old cyrus mailserver already uses these non-unique mailbox guids.

Is it necessary to have them unique over all private namespaces? Thanks Christian

----------------ursprüngliche Nachricht----------------- Von:Christian Binder Stadt Freilassing [christian.binder@freilassing.de ] An:"dovecot dovecot.org" [dovecot@dovecot.org ] Datum:Thu, 29 Jan 2015 09:24:12 +0100

Sorry if this is a duplicate message. I'm new in this mailing list and not sure if the first message really got posted ...

Dovecot version:2.2.9

We're using doveadm backup to migrate user mailboxes from cyrus to dovecot. I defined a master user for the old cyrus mailserver in imapc backend to get access to all the mailboxes. Now I realized that after migration every user's "Inbox" or "Trash" on the new dovecot server has the same mailbox-guid, e.g:

User a: inbox dd9456... trash 5549cc...

User b: inbox dd9456... trash 5549cc...

Is this a wanted behaviour? If i do not migrate with doveadm backup and just manually create mailboxes, the mailbox-guids are globally unique, e.g:

User a: inbox dd9456... trash 5549cc...

User b: inbox c543fe... trash t49ccc...

Thanks! Christian