On 16.4.2013, at 20.45, Axel Luttgens <AxelLuttgens at swing.be> wrote: > Hello, > > At http://wiki2.dovecot.org/MailboxFormat/mbox: > > The UID for a new message is calculated from "last used UID" in > X-IMAP header + 1 > > Shouldn't it read "in X-UID header + 1" instead? No. Either X-IMAP: or X-IMAPbase: header.