Subject: Mailbox format invalidated

From: shelley@NTPSERVER (Shelley A Waltz)
Date: Mon, 24 Jul 1995 17:31:43 GMT

In using a shared account, accessed by three persons, all using pine,
occasionally I get "Mailbox format invalidated(consult expert).
Is there something special to do for a shared rw mailbox?  I *do not*
want to use IMAP.  I am running UNIX.  Is there a way to rescan the inbox?

thanks,
shelley

---

From: Mark Crispin <[email-masked]>
Date: Mon, 24 Jul 1995 17:23:48 -0700

> occasionally I get "Mailbox format invalidated(consult expert).

You can't have an mbox format folder open simultaneously read/write by
multiple users.

What happens is that when Pine detects that the folder's size has changed,
but that the new size is either smaller than before, or is larger but the
new data doesn't immediately begin with a start-of-message header.  That
means that something other than that particular Pine process or sendmail
rewrote the folder.  Pine has no idea what that other program (even
another Pine) did; it no longer knows where the messages are.

Pine is supposed to have locking to prevent this from happening (this is
why that locking is there!!), although this locking may have been diabled
and/or sabotaged by NFS at your local site.

> Is there something special to do for a shared rw mailbox?

The only way is to use an alternate format which permits multiple
simultaneous access, such as tenex or mh.  Read the Pine Technical notes
for more details on tenex format.  In tenex format, you can do all
read/write operations *except* for expunging deleting messages (expunge
requires exclusive access).

> I *do not*
> want to use IMAP.  I am running UNIX.

IMAP won't help you in this case anyway, unless NFS if between you and the
disk where the folder resides.  If so, then you *must* use IMAP (or log
onto the system which has that disk) since tenex format access will *NOT*
work well over NFS.  Contrary to popular belief, NFS does not fully
implement Unix filesystem semantics.  Multiple sharing with NFS involved
doesn't work.

> Is there a way to rescan the inbox?

Unfortunately, the only way is what you've already discovered; quit and
restart Pine.  That's pretty much the same as what any command to "rescan
the inbox" would have to do.

-- Mark --

DoD #0105, R90/6 pilot, FAX: (206) 685-4045  ICBM: N 47 39'35" W 122 18'39"
Science does not emerge from voting, party politics, or public debate.