Hi all,
I'm waiting for the virtual mailbox feature in order to make a single POP3 access to retrieve messages contained in all my mailbox folders. This is because I use webmail and other IMAP clients but my main workstation uses a POP3-only client.
I was wondering if there's a way to keep the name of the folder containing each message while retrieving via POP3. I guess this could be done by dynamically adding a header to messages at retrieval time. Is there a feature for this or a plugin API?
Otherwise I was thinking about modifying the messages themselves on the server using a script. However, such a script would need to be run when a IMAP user moves a message to a folder and I believe Dovecot doesn't provide a trigger/hook mechanism. I also don't know if modifying stored messages is allowed since it could break some caching/hashing mechanism.
Do you have any idea for this?
Thanks in advance and thanks to Timo for the great work!
- alessandro.On Jun 22, 2009, at 6:49 AM, Alessandro Ranellucci wrote:
I was wondering if there's a way to keep the name of the folder
containing each message while retrieving via POP3. I guess this
could be done by dynamically adding a header to messages at
retrieval time. Is there a feature for this or a plugin API?
It's possible to implement as a plugin, but it probably won't be all
that easy.
Otherwise I was thinking about modifying the messages themselves on
the server using a script. However, such a script would need to be
run when a IMAP user moves a message to a folder and I believe
Dovecot doesn't provide a trigger/hook mechanism.
There are copy/save virtual functions that you can override. For
example something similar to what antispam plugin does.
I also don't know if modifying stored messages is allowed since it
could break some caching/hashing mechanism.
Right. You can't modify existing messages. But at the time when a
message is copied to another mailbox, you can save a slightly
different version of it. This of course also means that you can't do
the copying by hard linking a file (assuming you're using maildir).
Hmm. Out of these two possibilities, I think it's easier to just
return a modified message from mail_get_stream(). You could probably
do something similar to what mbox does and use
i_stream_create_header_filter() where you simply return a new X-
Mailbox: header after the headers are sent.
On 22-06-2009 at 17:35, Timo Sirainen wrote:
Hmm. Out of these two possibilities, I think it's easier to just return a modified message from mail_get_stream(). You could probably do something similar to what mbox does and use i_stream_create_header_filter() where you simply return a new X-Mailbox: header after the headers are sent.
Thank you, Timo. I'll need to get familiar with Dovecot sources.
That would be implemented as a patch against the virtual plugin? Or as a patch against the maildir code?
- al.On Mon, 2009-06-22 at 18:40 +0200, Alessandro Ranellucci wrote:
On 22-06-2009 at 17:35, Timo Sirainen wrote:
Hmm. Out of these two possibilities, I think it's easier to just return a modified message from mail_get_stream(). You could probably do something similar to what mbox does and use i_stream_create_header_filter() where you simply return a new X-Mailbox: header after the headers are sent.
Thank you, Timo. I'll need to get familiar with Dovecot sources.
That would be implemented as a patch against the virtual plugin? Or as a patch against the maildir code?
I'm actually again beginning to wonder what's a good way to implement this. The main problem is that messages must never change and Dovecot relies on this. For example messages' virtual sizes are stored in dovecot.index.cache file. If you change the message, the virtual size and other similar cached metadata is broken. So simply changing the message stream in virtual mailboxes won't work, because the cached metadata would also have to be changed and that makes it much more difficult.
So the somewhat easy to implement possibilities require the X-Mailbox: header to exists always for non-virtual mailboxes too. You can either implement code that actually saves it to the maildir files, or you can write a plugin that overrides mail_get_stream() and adds the header, similar to how zlib plugin works.
On 22-06-2009 at 20:06, Timo Sirainen wrote:
So the somewhat easy to implement possibilities require the X-Mailbox: header to exists always for non-virtual mailboxes too. You can either implement code that actually saves it to the maildir files, or you can write a plugin that overrides mail_get_stream() and adds the header, similar to how zlib plugin works.
Nice! The zlib plugin seems a good start.
I guess I'll have to override just storage->v.mailbox_open and then mail->v.get_stream. Within get_stream() it seems that the mailbox name to put in my X-Mailbox: header is available as _mail->box->name. Am I right?
Thank you again!
- alessandro.On Jun 23, 2009, at 10:25 AM, Alessandro Ranellucci wrote:
Nice! The zlib plugin seems a good start.
I guess I'll have to override just storage->v.mailbox_open and then
mail->v.get_stream. Within get_stream() it seems that the mailbox
name to put in my X-Mailbox: header is available as _mail->box-name. Am I right?
Sounds right.
participants (2)
-
Alessandro Ranellucci
-
Timo Sirainen