The notorious outbox

[Darko Obradovic <dobradovic gmx de>]

Hi all,

I think it's a good idea to split out the outbox-issue from the review  
thread, I can't even trace/reference it there anymore. ;)

Being a pure IMAP-user like Joe I raised this topic long time ago, and  
made some progress on my thoughts since then.

With the current implementation it's not possible to assign it to a  
remote folder, I had a GUI-patch for this (in Bugzilla, probably  
outdated) and it failed on my server, which works fine otherwise.

But it's not the solution. Let's analyze when the outbox is needed by a  
user, and what renders it different from other mailboxes:

- no one cares for it as long as it's empty
- you'll never move messages into it
- it is important to see if messages are queued
- remote storage is a very difficult issue I realized

For a user, the outbox is just the queue, needed only in two cases:
- offline usage of the MUA
- SMTP-server is down

The fact that balsa uses it for instant sendings is wrong, it should  
have a hidden cache, or pass it directly to libesmtp or whatever.  
Another potential problem is that balsa will send all queued messages  
if you send one instantly. Apart from being unexpected by the user (he  
only clicked "send" on one message), it will lead to trouble if you  
implement different identities with different SMTP-accounts.

So I'd suggest to clearly separate the cache for one message being sent  
right now and the queue, which should only be a queue.

Now the interesting question is, whether the queue should be local or  
remote. I have no idea, I'll just provide two mutually exclusive  
scenarios which prove that there is no easy solution:

- assume you've composed a message at PC1 and want to send it, the  
SMTP-server is down, you'd like to send it later of course, when you  
are at PC2 -> remote queue

- assume this message uses a SMTP-account only accessible from and  
configured at PC1, if you are on PC2, the SMTP-account isn't usable at  
all, an IMAP-server doesn't know anything about sending, so why to  
store messages there? -> local queue

bye,

Darko