On 20/01/2024 21:25 EET Barbara M. <barbara@rfx.it> wrote: Already done a first migration using imapsync Good result, but there is the POP3 UIDs problem. Searching online give a Tried to understand the instructions on: https://doc.dovecot.org/settings/plugin/pop3-migration-plugin/? with limited comprension results (the link in the page is to the old wiki). Searching online give more confusion ... I am obviouly interested to resync the INBOX with somethig that give to clients the old UIDs so they don't re-download all messages in the inbox as duplicates into their mailbox. I suppose I can do: doveadm -v expunge -u <username> mailbox INBOX all rm dovecot* in the Maildir folder doveadm force-resync -u <username> INBOX then use dsync to migrate the INBOX Here I need some hints to how setup it and wich syntax use. If useful I can copy or mount the /var/mail/ folder of the old server that contains the users INBOX to the new server. Thanks, B Hi! Please see https://doc.dovecot.org/admin_manual/migrating_mailboxes/ for instructions. Aki