On 20 Jul 2018, at 15.20, Fineware PM <postmaster@fineware.it> wrote:

if I dump the index of inbox :
"doveadm -v dump example.com/user/idx/mailboxes/INBOX/dovecot.index
 
I don't find the message.

I think is corrupted the index



try then running: doveadm force-resync -u user "*"

Sami