Re: [Dovecot] Keep pop messages, is it possible?

2008-01-15 Thread Bill Cole

At 8:23 PM -0800 1/14/08, Jeff Grossman wrote:

Fábio M. Catunda wrote:

Hi!

I would like to find a way to not delete 
messages when they are downloaded via pop3, is 
that possible with dovecot?


Gmail do this, I dont know how they mark 
messages that have been downloaded to avoid 
clients to download it again, but it looks like 
a good resource!


Thanks for the help!
That is a feature of the client.  Most clients 
have a setting which says Keep Messages On 
Server.


That's almost always correct: normal client-based 
POP3 server retention is entirely dependent on 
clients that  keep track of what messages they 
have or have not downloaded, and some POP3 
servers also maintain a Status header so that 
multiple clients can look at the same message and 
know whether another client has already read it.


GMail goes a bit further, in a somewhat useful 
fashion. Their POP3 server acts mostly like an 
auto-deleting server: once a message has been 
retrieved by POP3, it will not be seen on later 
POP3 sessions, even though it is retained in the 
GMail Inbox. Mail deleted by a POP3 or IMAP 
client is removed from the Inbox, but remains in 
the All Mail dump as well as in whatever 
labelled collection it is in. Frankly, that 
behavior is positively weird and arguably 
dysfunctional from a POP3 perspective, but then 
POP3 really isn't designed with a server-based 
persistent mailstore in mind.


It is my understanding that there is widespread 
principled aversion to the Status header (which 
is understandable) so that's likely not to happen 
for Dovecot. The GMail message hiding for POP3 
seems to me like a recipe for disaster for anyone 
not willing to provide essentially unlimited 
permanent storage for mail, since it effectively 
hides mail from POP3 users without deleting it.


--
Bill Cole
[EMAIL PROTECTED]



Re: [Dovecot] Keep pop messages, is it possible?

2008-01-15 Thread Fábio M. Catunda

Thanks for the answer Bill!

I see this a behavior as a good feature, seems like gmail just mark the 
message as read when you download if via pop and the pop server consider 
this information at the time to serve clients, it looks a pretty clean 
solution for me.


I do agree that this is probably not compliant with pop3 protocol, but, 
sometimes you can break a RFC to serve a good service and sometimes a 
RFC is rewrited to agree with a good new feature (have a look in SIP 
evolution).


I will try to do a plugin for that when I have time!

Thanks!


That's almost always correct: normal client-based POP3 server 
retention is entirely dependent on clients that  keep track of what 
messages they have or have not downloaded, and some POP3 servers also 
maintain a Status header so that multiple clients can look at the same 
message and know whether another client has already read it.


GMail goes a bit further, in a somewhat useful fashion. Their POP3 
server acts mostly like an auto-deleting server: once a message has 
been retrieved by POP3, it will not be seen on later POP3 sessions, 
even though it is retained in the GMail Inbox. Mail deleted by a POP3 
or IMAP client is removed from the Inbox, but remains in the All 
Mail dump as well as in whatever labelled collection it is in. 
Frankly, that behavior is positively weird and arguably dysfunctional 
from a POP3 perspective, but then POP3 really isn't designed with a 
server-based persistent mailstore in mind.


It is my understanding that there is widespread principled aversion to 
the Status header (which is understandable) so that's likely not to 
happen for Dovecot. The GMail message hiding for POP3 seems to me like 
a recipe for disaster for anyone not willing to provide essentially 
unlimited permanent storage for mail, since it effectively hides mail 
from POP3 users without deleting it.






Re: [Dovecot] Keep pop messages, is it possible?

2008-01-14 Thread Jeff Grossman

Fábio M. Catunda wrote:

Hi!

I would like to find a way to not delete messages when they are 
downloaded via pop3, is that possible with dovecot?


Gmail do this, I dont know how they mark messages that have been 
downloaded to avoid clients to download it again, but it looks like a 
good resource!


Thanks for the help!
That is a feature of the client.  Most clients have a setting which says 
Keep Messages On Server.


Jeff


[Dovecot] Keep pop messages, is it possible?

2008-01-14 Thread Fábio M. Catunda

Hi!

I would like to find a way to not delete messages when they are 
downloaded via pop3, is that possible with dovecot?


Gmail do this, I dont know how they mark messages that have been 
downloaded to avoid clients to download it again, but it looks like a 
good resource!


Thanks for the help!