Imap synchronisation failure with READ-ONLY status

[David Soulayrol]

Hello.

I'm considering to drop isync in favour of offlineimap. I have first
tried on a first imap server with few messages, and synchronisation
went perfectly both ways. Then I have tried to synchronize to my main
server, and it seemed to go well on download, but I can upload no
modification at all. This happens on the imap server from the free.fr
domain. I have taken a capture with IMAP logs (expunged here for
clarity), and my problem occurs here:

 DEBUG[imap]:   25:20.17 > JMMH36 SELECT INBOX
 DEBUG[imap]:   25:20.19 < * 163 EXISTS
 DEBUG[imap]:   25:20.19 < * 0 RECENT
 DEBUG[imap]:   25:20.19 < * OK [UNSEEN 120] mailbox contains unseen messages
 DEBUG[imap]:   25:20.19 < * OK [UIDVALIDITY 1] UIDs are valid for this mailbox
 DEBUG[imap]:   25:20.19 < * OK [UIDNEXT 250989] next expected UID is 250989
 DEBUG[imap]:   25:20.19 < * FLAGS (\Answered \Deleted \Draft \Flagged
\Seen $Forwarded $MDNSent Forwarded $Junk $NotJunk Junk JunkRecorded
NonJunk NotJunk receipt-handled)
 DEBUG[imap]:   25:20.19 < * OK [PERMANENTFLAGS (\Answered \Deleted
\Draft \Flagged \Seen $Forwarded $MDNSent Forwarded receipt-handled
\*)] junk-related flags are not permanent
 DEBUG[imap]:   25:20.19 < * OK [HIGHESTMODSEQ 1130080] modseq tracked
on this mailbox
 DEBUG[imap]:   25:20.25 < JMMH36 OK [READ-WRITE] SELECT completed
 DEBUG[imap]:   25:20.25 > JMMH37 UID STORE 247650 +FLAGS (\Seen)
 DEBUG[imap]:   25:20.27 < JMMH37 NO mailbox selected READ-ONLY
 DEBUG[imap]:   25:20.27 NO response: mailbox selected READ-ONLY

I do not talk the imap everyday, so I've checked what occured when
using telnet on that server, and everything passed ok.

 $ telnet imap.free.fr 143
 Trying 212.27.42.94...
 Connected to imap.free.fr.
 Escape character is '^]'.
 * OK [CAPABILITY IMAP4REV1 X-NETSCAPE LOGIN-REFERRALS AUTH=LOGIN]
IMAP4rev1 Free
 JMMH35 login *****
 JMMH35 OK [CAPABILITY IMAP4rev1 ACL BINARY CATENATE CHILDREN
CONDSTORE ENABLE ESEARCH ID IDLE LIST-EXTENDED LITERAL+
LOGIN-REFERRALS MULTIAPPEND NAMESPACE QRESYNC QUOTA RIGHTS=ektx
SASL-IR SEARCHRES UIDPLUS UNSELECT WITHIN] LOGIN completed
 JMMH36 SELECT INBOX
 * 163 EXISTS
 * 0 RECENT
 * OK [UNSEEN 120] mailbox contains unseen messages
 * OK [UIDVALIDITY 1] UIDs are valid for this mailbox
 * OK [UIDNEXT 250989] next expected UID is 250989
 * FLAGS (\Answered \Deleted \Draft \Flagged \Seen $Forwarded $MDNSent
Forwarded $Junk $NotJunk Junk JunkRecorded NonJunk NotJunk
receipt-handled)
 * OK [PERMANENTFLAGS (\Answered \Deleted \Draft \Flagged \Seen
$Forwarded $MDNSent Forwarded receipt-handled \*)] junk-related flags
are not permanent
 * OK [HIGHESTMODSEQ 1130080] modseq tracked on this mailbox
 JMMH36 OK [READ-WRITE] SELECT completed
 JMMH37 UID STORE 247650 +FLAGS (\Seen)
 * 127 FETCH (FLAGS (\Seen) UID 247650)
 JMMH37 OK UID STORE completed
 Connection closed by foreign host.

What seems to differ is only the server response when trying to change
the flag and I can't find a reason for the difference. I've also tried
to remove a message; it failed with offlineimap but I succeeded in
setting the Deleted flag and expunging it manually.

Could anyone help?
--
David