Re: [imap5] Designing a new replacement protocol for IMAP

[Adrien de Croy <[e-mail]>]

Whilst HTTP could certainly be used to put together an email system, I 
don't think it would perform well enough to replace existing protocols 
on desktops.

The main issues I see are:

* updates.  Would need to poll or use long polling to get real-time 
updates (e.g. notification of incoming mail).
* slow.  Gut feel based on 17 years writing http proxies is that it 
would be too slow
* complex.  In order to reduce round-trips, you'd have to do many things 
in a single transaction, which would create complexity issues in the 
server and client
* protocol bloat.  if you think IMAP is bloated, try HTTP.
* fundamentally an off-line style protocol for mail, which has strong 
incentives to be online (esp for in-office use).

I think it would also be very problematic in the wild, since any http 
intermediary would feel entitled to mess with traffic.  E.g. heuristic 
caching, intercepting proxies etc.

It's almost too ubiquitous.  Everyone and their dog thinks they know how 
http works.  It's not strictly-enough defined, and has a LOT of optional 
features which aren't relevant for mail (e.g. content negotiation).  
Interop in http is already problematic, but start getting people writing 
mail servers in php etc, and see what starts to happen.  I think it 
would be a nightmare.

Adrien


On 9/02/2012 8:20 p.m., Thomas Koch wrote:
> Bron Gondwana:
>> Snide comments from those who don't agree with the goals are welcome too...
>> I just won't listen to you.  These goals are very important to me.
> Hi Bron,
>
> I'm not an expert in IMAP, just got here out of curiosity about Kolab[1]'s use
> of IMAP folders as data stores.
> I found some older initiatives to replace IMAP with an HTTP based approach.[2]
> What do you think of HTTP for mail access? For my bachelor thesis[3] I
> currently argue that CardDAV/CalDAV could be perfectly replaced by AtomPub
> (RFC 5023).
> The main advantage would be that most software developers on this planet have
> some vague understanding of HTTP and that imense infrastructure and software
> already exists.
>
> [1] http://wiki.kolab.org/Why_IMAP_Is_Used_For_Storage
> [2] http://www.prescod.net/rest/restmail/
>      https://www.ietf.org/mailman/listinfo/httpmail
> [3] https://github.com/thkoch2001/bachelor-thesis
>
> Best regards,
>
> Thomas Koch, http://www.koch.ro
>

-- 
Adrien de Croy - WinGate Proxy Server - http://www.wingate.com