dovecot - Mar 2019 - Restoring mailboxes from backup duplicates messages in POP clients

Hello

I had a disk problem and had to reformat it. All mailboxes were backed 
up using rsync.
After I restored the mailboxes, the POP clients (Thunderbird) that were 
configured to leave the messages on the mailserver for, let's say, 30 
days, didn't understand that some messages were already transfered and 
the users got duplicated messages in their Inbox.
How can we avoid this?

-- 

Thanks

Lu?s F. Gomes
IT Manager
(55)(21) 3527-1220
Departamento de Engenharia El?trica
PUC-Rio
R. Marques de S. Vicente 225/401L
22451-900 - Rio de Janeiro/RJ

Hello
>
> I had a disk problem and had to reformat it. All mailboxes were backed 
> up using rsync.
> After I restored the mailboxes, the POP clients (Thunderbird) that 
> were configured to leave the messages on the mailserver for, let's 
> say, 30 days, didn't understand that some messages were already 
> transfered and the users got duplicated messages in their Inbox.
> How can we avoid this?
>
-- 
Thanks
Lu?s Fernando V. Gomes
IT Manager
(55)(21) 3527-1220
Departamento de Engenharia El?trica
PUC-Rio
R. Marques de S. Vicente 225/401L
22451-900 - Rio de Janeiro/RJ - BR

On Wed Apr 10 2019 09:13:41 GMT-0400 (Eastern Standard Time), Luis F. V.
Gomes via dovecot <dovecot at dovecot.org> wrote:
> I had a disk problem and had to reformat it. All mailboxes were backed 
> up using rsync.
> After I restored the mailboxes, the POP clients (Thunderbird) that 
> were configured to leave the messages on the mailserver for, let's 
> say, 30 days, didn't understand that some messages were already 
> transfered and the users got duplicated messages in their Inbox.
> How can we avoid this?
Don't use rsync, use the built in dovecot backup capability?