[Dovecot] Envelope From changed - why?

[Tom Alsberg]

Hi there.
Please read my comments below:

On Tue, Apr 27, 2004 at 10:49:51AM -0400, Amelia A Lewis wrote:
> On Tue, Apr 27, 2004 at 03:53:39PM +0300, Tom Alsberg wrote:
> >That's possible.  But I'd prefer it if when COPYing a message, it 
> >would just copy the "From " line verbatim as well, and not get into 
> >this trouble, even though I see now that the content should normally
> >be the same (leave those semantics to the MTA...).
> 
> Okay, so this is the IMAP COPY command, right?

Yes...

> Why are you putting mbox "From " lines into my maildir?

Uhmm, I am not.  It should of course only copy it together with the 
"From " line if copied to an mbox...

> If dovecot is the source, how does it know what format the target 
> mailbox is in?

Well, it obviously knows what format the target mailbox is in already,
as it needs it to be able to write to it properly anyway...

> Should dovecot instances communicate with one another?

I'm not sure I understand you.

Well, from what I've seen in the code, in no occassion does the COPY
command work between processes.  When COPYing a message, it just reads
the message (from an istream or something like that, don't remember 
exactly right now), and writes the message to the target mailbox (in
the same process - called from within the same routine), and in the 
case of mbox, the writing routine first calls mbox_from_create to 
write the "From " line.

It could, when COPYing from an mbox to and mbox, copy the message 
together with the "From " line to the target mbox, instead of calling
mbox_from_create to write a new "From " line and then copying the
rest.

Given that every user can only access his mailboxes, and there is one
process per connected user, I fail to see how any interaction between
dovecot instances is necessary.

> Is this only for mailboxes that a single dovecot instance is in 
> charge of? 

What do you mean by a "dovecot instance"?  Do you mean one server,
or one forked process, or what?

> So the move, although issued as IMAP, should behave differently for 
> a move between two mailboxes on one server than it does between 
> mailboxes on two servers?

Can IMAP move messages between servers?  (Can IMAP servers communicate
amongst them?)  I don't think that I understand...

As far as I understood IMAP (from the RFC, docs, etc.), within one
session, it only operates on a defined mailbox/folder space (the 
folders accessible to the user after he's authenticated).  There's
no sending of messages through IMAP (modifying/appending to own
mailboxes doesn't count)...

> If dovecot is moving messages from one folder (that it "owns") to 
> another folder (that it "owns"), how much of the format-specific 
> information should be copied, if it has been instructed to do an 
> IMAP copy?  When does the difference in semantics between a 
> server-internal IMAP COPY versus an inter-server IMAP COPY become 
> anti-intuitive?

You'll have to explain me what I'm missing...  I don't understand
what you mean by an "inter-server IMAP COPY".  However, if something
like that exists, I still believe that when possible (e.g. the COPY
is between two mbox folders in the same server, which is usually the
case in a server based solely on mbox), it should preserve the format
(the "From " line).

Modifying the "From " line with no reason is counter-intuitive in the
first place...  If users in the installation access their mailboxes 
only by IMAP, though, then it does not matter, and then some 
inconsistency (preserving the "From " line only when possible) does
not hurt since it is not visible at all.

> Amy!

  I'm sorry for my ignorance, enlighten me...
  -- Tom

-- 
  Tom Alsberg - hacker (being the best description fitting this space)
  Web page:	http://www.cs.huji.ac.il/~alsbergt/
DISCLAIMER:  The above message does not even necessarily represent what
my fingers have typed on the keyboard, save anything further.