[Dovecot] Question about the pop3 feature "leave messages on server for a certain period of time"

[Δημήτριος Καραπιπέρης]

O/H Leonardo Rodrigues έγραψε:
> Axel Luttgens escreveu:
>>
>> No, I don't think to have omitted anything: I already replied to the 
>> OP wrt the 'leave messages on server' matter.
>>
>> Here, I was replying to Leonardo (who's not the OP) who started a new 
>> idea (a potentially misleading POP vs IMAP debate) within the 
>> original thread.
>>
>
>    Starting the POP vs IMAP war was not my intention and i really 
> would like to say i'm sorry for that. My intention was to show the OP 
> that, in the proposed scenario (same user with multiple MUAs trying to 
> use leave message on server and have a intelligent behavior of that 
> client-side feature), working with IMAP would a better choice (and 
> smart one, in MY opinion), because keeping messages synced between 
> several MUAs (let's not forget webmail is a pretty common second MUA 
> used by users, usually a IMAP MUA) and server is part of IMAP protocol 
> and does not depends on MUA behaviors or 'algorithms'. Everything is 
> part of IMAP protocol, the $imapuser could even change MUA how many 
> times he wants to and there would be no accidental loss of messages.
>
>    Of course if some IMAP MUA has some client-side feature configured, 
> like 'delete messages older than N days' configured, we can have some 
> messages being deleted despite of user's will ...  but that would NOT 
> be an accidental loss of messages, that would be a EXPECTED loss of 
> messages because of some MUA configuration.
>
>    All the 'leave message on server' used by POP clients is NOT part 
> of the POP protocol (yes i know POP is pretty well RFC-defined, but 
> not those client-side features, as well as some IMAP client-side 
> features are not RFC-defined as well).
>
>    The major problem here seems to be the fact that for the POP3 
> server (dovecot or any other), the 'leave messages on server' feature 
> simply does not exists. It may be guessed by the 'RETR' not followed 
> by 'DELE' which usually happens, but that would be just a guess. 
> There's no way to the server to control what will happen with that 
> client-side feature and different MUAs accessing the same mailbox with 
> POP3. The proposed of used the expire plugin would solve a different 
> situation, not the initially proposed one.
>
>    I use IMAP4 in some situations and use POP3 in others as well. I 
> think IMAP4 is a better protocol nowadays, with fast internet 
> connections and storages on server becaming cheaper each day. But it 
> doesnt means POP3 is dead. But in some situations, like users who 
> really needs the 'leave messages on server' feature, using pop3 is not 
> a smart decision anymore. Which doesnt means everybody should stop 
> using POP3 and changing to IMAP4 ....
>
>    Dimitrios, i really think you'll have a hard time trying to find a 
> server-side feature to control that mess of using leave messages on 
> server with different MUAs by the simply fact that, in the server 
> side, that thing simply does not exist.
>
Leonardo,
I am pretty sure , years now, that IMAP4 is better suited for my needs 
and I am trying to change my organizations ethos, well established for 
years now.
Centralized controlled mechanism in terms of e-mail usage, is by all 
means more convenient for the simple reason that everyone wants his 
e-mail corpus available
from everywhere.
Thank u all for your replies.

D.