Re: offlineimap / uw-imapd / mutt

[John Goerzen <jgoerzen@xxxxxxxxxxxx>]

On Sun, Apr 20, 2003 at 09:53:06AM +1000, Andrew Cowie wrote:
> It seems to happen to me a lot though. What do I do about it?

Well, like I said, you could first try not accessing the folders directly on
the server.  If you want to use mutt directly on the server, point it to
localhost's IMAP server.

My recommendation is to avoid UW-IMAPd.  Others have reported this problem
before.  From the manual:

   UID VALIDITY PROBLEM FOR FOLDER
       IMAP  servers  use  a  unique  ID (UID) to refer to a specific message.
       This number is guaranteed to be unique to a particular message forever.
       No  other  message in the same folder will ever get the same UID.  UIDs
       are an integral part of OfflineIMAP's synchronization scheme; they  are
       used to match up messages on your computer to messages on the server.

       Sometimes,  the  UIDs on the server might get reset.  Usually this will
       happen if you delete and then recreate a folder.   When  you  create  a
       folder,  the  server  will  often  start  the  UID  back  from  1.  But
       OfflineIMAP might still have the UIDs from the previous folder  by  the
       same  name stored.  OfflineIMAP will detect this condition and skip the
       folder.  This is GOOD, because it prevents data loss.

   [snip]

       Some  IMAP servers are broken and do not support UIDs properly.  If you
       continue to get this error for all your folders even  after  performing
       the above procedure, it is likely that your IMAP server falls into this
       category.   OfflineIMAP  is  incompatible  with  such  servers.   Using
       OfflineIMAP  with them will not destroy any mail, but at the same time,
       it will not actually synchronize it either.  (OfflineIMAP  will  detect
       this condition and abort prior to synchronization.)


> Deleting the offlineimap.uidvalidity file seems to do it, but then
> causes a [re]download of everything?

Yes, because all the UIDs are messed up on the server, and OfflineIMAP no
longer has any reliable way to correlate messages on your local disk with
those on the IMAP server.