$ exchange2mbox -p hschurig -m mbox
Message-ID: <E2D5308820E3A04A8F3074E9B29FE4B9010BB2@dgmail.datagroup.local> added to profile hschurig
Message-ID: <E2D5308820E3A04A8F3074E9B29FE4B90122EF@dgmail.datagroup.local> added to profile hschurig
Message-ID: <E2D5308820E3A04A8F3074E9B29FE4B9F887@dgmail.datagroup.local> added to profile hschurig
Message-ID: <E2D5308820E3A04A8F3074E9B29FE4B9F87F@dgmail.datagroup.local> added to profile hschurig
Message-ID: <E2D5308820E3A04A8F3074E9B29FE4B984A3@dgmail.datagroup.local> added to profile hschurig

So far: OK !

$ openchangeclient -p hschurig -t "hschurig" -s "Blah" -B "Test" --sendmail
    sendmail                 : MAPI_E_SUCCESS (0x0)
schurig@mnz66:/usr/src/openchange$ exchange2mbox -p hschurig -m mbox
Message-ID: <E2D5308820E3A04A8F3074E9B29FE4B92D64@dgmail.datagroup.local> added to profile hschurig

Again OK

Now I deleted, in the mbox file, the just retrieved dummy message. I deleted all blank lines at the end of the mbox file as well.

$ exchange2mbox -p -m mbox -u
{+] Synchonizing mbox with Exchange mailbox
<E2D5308820E3A04A8F3074E9B29FE4B9010BB2@dgmail.datagroup.local> deleted from the Exchange server
<E2D5308820E3A04A8F3074E9B29FE4B90122EF@dgmail.datagroup.local> deleted from the Exchange server
<E2D5308820E3A04A8F3074E9B29FE4B9F887@dgmail.datagroup.local> deleted from the Exchange server
<E2D5308820E3A04A8F3074E9B29FE4B9F87F@dgmail.datagroup.local> deleted from the Exchange server
<E2D5308820E3A04A8F3074E9B29FE4B984A3@dgmail.datagroup.local> deleted from the Exchange server
<E2D5308820E3A04A8F3074E9B29FE4B92D64@dgmail.datagroup.local> deleted from the Exchange server
    MapiLogonEx              : MAPI_E_NOT_FOUND (0x8004010F)

Please note that I made an error specifiying my profile (I wanted to delete it, now that I have marked it as a default). It seemed to have deleted messages in excess!

However, omitted the -p again seemed to help:

$ exchange2mbox -m mbox -u
[+] Adding <E2D5308820E3A04A8F3074E9B29FE4B9010BB2@dgmail.datagroup.local> to hschurig
[+] Adding <E2D5308820E3A04A8F3074E9B29FE4B90122EF@dgmail.datagroup.local> to hschurig
[+] Adding <E2D5308820E3A04A8F3074E9B29FE4B9F887@dgmail.datagroup.local> to hschurig
[+] Adding <E2D5308820E3A04A8F3074E9B29FE4B9F87F@dgmail.datagroup.local> to hschurig
[+] Adding <E2D5308820E3A04A8F3074E9B29FE4B984A3@dgmail.datagroup.local> to hschurig
[+] mbox already synchronized with Exchange Mailbox

Just the last message is wrong, it was NOT "already" synchronized.

But the folder in the webmail is now still empty.