[Dovecot] dovecot as gmail imap proxy

[Farkas Levente]

Timo Sirainen wrote:
> On Jun 17, 2008, at 6:14 PM, Timo Sirainen wrote:
> 
>> On Jun 17, 2008, at 6:03 PM, Farkas Levente wrote:
>>
>>> would it be possible to create a dovecot server as an imap proxy for 
>>> gmail and google apps?
>>> imho many people/company would be love to use such a setup where he 
>>> can use gmail in vacation or any other time, but when the email is 
>>> real critical apps (not acceptable to wait 1 minutes for an email to 
>>> load or to open a folder/label) than he can use a proxy server eg. 
>>> dovecot which act as a imap proxy to gmail and can be hosted on 
>>> closer, faster server and this speed problem never happend. what's 
>>> more it can be used as a mail backup server too.
>>
>> I've thought about a caching IMAP mail storage backend for Dovecot and 
>> even started implementing it once, but it didn't get very far. If 
>> someone wants to try to continue it, I can send what I've written so 
>> far. Although it's mostly a copy of cydir backend with a tiny bit of 
>> it replaced with IMAP code.
> 
> Now that I think of it, the IMAP backend should do only direct IMAP 
> backend accessing and if caching is wanted it could be a generic middle 
> layer. Might be also useful for other things like caching mails from NFS 
> server. Although Linux already has a cachefs for that.

yes, that's exactly what i'm thinking about. all imap command which 
issued by the client to the middle layer should have to propagate back 
to the backed (in this case gmail). but imho the hard part that we've to 
assume that the backend (in this case gmail) is slow, so the middle 
layer have to cache the imap commands to be able to propagate all 
command to the backend (and command queue for all mailbox). so if the 
connection between dovecot and gmail are fast then both has the same 
messages and flags, etc. if the connection is slow than gmail may have a 
small delay, but this delay probably won't be visible to the user (if he 
not use the web interface at the same time too).


-- 
   Levente                               "Si vis pacem para bellum!"