[Dovecot] Plugin when downloading mail

[Ed W]

Timo Sirainen wrote:
> On Aug 14, 2008, at 11:12 AM, <martijn at youngguns.nl> 
> <martijn at youngguns.nl> wrote:
>
>> Is there a way to modify mail messages when they are downloaded using a
>> special login.
>
> In theory, yes.
>
>> eg. my normal login for dovecot is martijn at youngguns.nl but when I 
>> log in
>> using martijn at dosomething.youngguns.nl I would like to download my mail
>> which are processed using a Perl script. The Perl script will modify the
>> content of the message (the message body). So I don't want to change the
>> header or IMAP flags.
>
> There are some problems with that. You'd have to have separate index 
> files for the accounts so that Dovecot won't return wrong cached 
> values (or disable indexes for the other login). I think the plugin 
> could work very much like the zlib plugin works now (override struct 
> mail.get_stream()). Just make sure it always returns exactly the same 
> output, because IMAP guarantees that the messages are immutable (and 
> e.g. fetching RFC822.SIZE must match your modified message's size).
>

Another solution would be to maintain parallel mailboxes by whatever 
means and keep them in sync.  This may not be as hard as it sounds 
depending on requirements?  I think the "log" module might provide a 
starting point to make this really watertight?

Have you more details on your requirements?  Is it a low bandwidth problem?

In my solution we simply enable a filter on incoming email and then keep 
a copy of the old email in an Archive folder
http://www.mailasail.com

Good luck

Ed W