Re: what is the benefit of imap? Another meta-question.
Hi, * David Champion wrote: [ POP3 needs locking ] That's implementation-dependent though. A server might require locking, but it's not inherent to the protocol and it's possible to implement one that has few of the contstraints that people have mentioned in this thread. RfC1939 explicitely states that the maildrop (mailbox) needs to be locked once a client is authenticated, see section 4. It doesn't say what exactly the lock means, though. At least I read it like that. /nitpick Rocco
Re: what is the benefit of imap? Another meta-question.
RfC1939 explicitely states that the maildrop (mailbox) needs to be locked once a client is authenticated, see section 4. It doesn't say what exactly the lock means, though. At least I read it like that. This is drifting pretty far away from mutt, and I doubt any of us are writing new POP client code, so I'll keep this shortish. :) I imagine that I understand why the draft suggests a mailbox lock, but I think it's wrong to interpret that as a real requirement of POP. RFC 1939 predates BCP-14 (RFC 2119) and no MUST/SHOULD is present. Absent such terminology (and reasons for using it) I think that a protocol RFC doesn't get to prescribe the exact behavior of the server as long as the interface goals are met, and this can be done without an exclusive lock on the whole mailbox. What 1939 describes may be necessary for some server implementations, but not for all. -- -D.d...@uchicago.eduNSITUniversity of Chicago Just to clear the deck, I own no monkeys.
Re: what is the benefit of imap? Another meta-question.
On Wed, Mar 18, 2009 at 11:51:56PM -0600, Paul E Condon wrote: Another meta-question, where can I find a straight-forward description of imap, without the enthusiastic pushing? What is it? it's just a protocol to access email on a remote server. that description would apply to pop3 as well. the difference between them is that imap leaves the messages on the server, while pop3 downloads them to the local machine. for that reason, imap has ways to perform actions such as copying/moving and deleting messages on the server. imap basically makes the remote server accessible to your mail client as if it were (a set of) local mail folders. Not in some narrow sense, but what is involved in 'being an imap user'? first, your mail server has to support it. then you simply set up your mail client to use imap. (or preferably imaps.) that's about it. -- Joost Kremers, PhD University of Frankfurt Institute for Cognitive Linguistics Grüneburgplatz 1 60629 Frankfurt am Main, Germany
Re: what is the benefit of imap? Another meta-question.
On Thu, Mar 19, 2009 at 07:06:12AM +0100, Joost Kremers wrote: On Wed, Mar 18, 2009 at 11:51:56PM -0600, Paul E Condon wrote: Not in some narrow sense, but what is involved in 'being an imap user'? first, your mail server has to support it. then you simply set up your mail client to use imap. (or preferably imaps.) that's about it. Well, that and the ceremony with the goat. Wait! That's secre... I mean, there's no ceremony! grin Ed signature.txt Description: Digital signature
Re: what is the benefit of imap? Another meta-question.
On Thu, Mar 19, 2009 at 02:18:01AM -0400, Ed Blackman wrote: On Thu, Mar 19, 2009 at 07:06:12AM +0100, Joost Kremers wrote: On Wed, Mar 18, 2009 at 11:51:56PM -0600, Paul E Condon wrote: Not in some narrow sense, but what is involved in 'being an imap user'? first, your mail server has to support it. then you simply set up your mail client to use imap. (or preferably imaps.) that's about it. Well, that and the ceremony with the goat. Wait! That's secre... I mean, there's no ceremony! no goat, no ceremony, and no bucket of lard either! *g* -- Joost Kremers, PhD University of Frankfurt Institute for Cognitive Linguistics Grüneburgplatz 1 60629 Frankfurt am Main, Germany
Re: what is the benefit of imap? Another meta-question.
On Thu, Mar 19, 2009 at 07:06:12AM +0100, Joost Kremers wrote: On Wed, Mar 18, 2009 at 11:51:56PM -0600, Paul E Condon wrote: Another meta-question, where can I find a straight-forward description of imap, without the enthusiastic pushing? What is it? it's just a protocol to access email on a remote server. that description would apply to pop3 as well. the difference between them is that imap leaves the messages on the server, while pop3 downloads them to the local machine. *By default* in both cases. There's nothing that actually forces you to leave mail on an IMAP server, neither is there anything that forces you to remove mail when you download it from a POP3 server. However most POP3 services expect you to remove mail when you download it and most IMAP services expect you to keep mail on the server. -- Chris Green
Re: what is the benefit of imap? Another meta-question.
Hi, * Joost Kremers wrote: so the leave mail on server option that most pop-clients have is certainly not a convenient way to access your mail remotely from different locations. Plus: POP needs locking, i.e. only one client at a time can access the mailbox which implies that tools should not perform time-consuming tasks while they have a POP session open. Rocco
Re: what is the benefit of imap? Another meta-question.
On Thu, Mar 19, 2009 at 09:02:12AM +, Chris G wrote: *By default* in both cases. There's nothing that actually forces you to leave mail on an IMAP server, neither is there anything that forces you to remove mail when you download it from a POP3 server. However most POP3 services expect you to remove mail when you download it and most IMAP services expect you to keep mail on the server. it's a little more than that. pop was designed with the former in mind, imap with the latter. pop doesn't have the facilities to treat a remote mailbox the same way as a local one. you can leave the mail on the server with pop, but that's about it. it certainly doesn't allow you to store sent mail on the server, or move messages from one mailbox to another on the server. so the leave mail on server option that most pop-clients have is certainly not a convenient way to access your mail remotely from different locations. -- Joost Kremers Life has its moments
Re: what is the benefit of imap? Another meta-question.
I think the best summary is that IMAP is a remote mailbox access protocol, supporting all common mailbox operations at the protocol level. POP is not: it supports full message retrieval, new-message scan (kind of, via UIDL), and deletion. This makes it, at best, a queued message pull protocol. But as someone else said, IMAP is just more flexible. You may not need all the features of IMAP, but since it fully encompasses everything that POP supports, why not use it? so the leave mail on server option that most pop-clients have is certainly not a convenient way to access your mail remotely from different locations. If you have minimal needs, it works alright. It's implementation- dependent since it's not done at the protocol level, but POP servers can track basic message and mailbox status. Plus: POP needs locking, i.e. only one client at a time can access the mailbox which implies that tools should not perform time-consuming tasks while they have a POP session open. That's implementation-dependent though. A server might require locking, but it's not inherent to the protocol and it's possible to implement one that has few of the contstraints that people have mentioned in this thread. But historically, there are few really good POP servers, so in practical terms you're not wrong. Most of the things that people cite as flaws of POP are really flaws in particular implementations, not in the protocol. The POP protocol is limited in scope, but I don't think this is a flaw; POP just has a different design goal. (That said, it's really too bad that the POP and NNTP groups didn't join forces from the start. With an NNTP server that supported authentication and operationally understood the goals of user-oriented mailbox access, it would have been a completely reasonable alternative to both POP and IMAP, and much closer to IMAP in spirit.) -- -D.d...@uchicago.eduNSITUniversity of Chicago Just to clear the deck, I own no monkeys.
Re: what is the benefit of imap? Another meta-question.
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Thursday, March 19 at 10:42 AM, quoth David Champion: I think the best summary is that IMAP is a remote mailbox access protocol, supporting all common mailbox operations at the protocol level. POP is not: it supports full message retrieval, new-message scan (kind of, via UIDL), and deletion. This makes it, at best, a queued message pull protocol. Well, if you're comparing IMAP to POP, one of the common comparisons between them is that POP's simplicity lends itself to much more simple and lightweight server implementations. Thus, these implementations are easy to audit, easy to secure, and require less hardware to support hundreds of thousands of users. IMAP makes operations like server-side sorting and arbitrary tagging available and that puts more work on the server. IMAP clients are likely to stay connected for hours at a time (rather than poll periodically), and have a habit of keeping multiple connections open, making it easy for a single IMAP server to run out of ports if its supporting a large number of clients. POP3 clients rarely use multiple connections, and poll periodically instead of keeping a connection open, and thus POP3 servers are unlikely to run out of ports, but IMAP servers supporting large numbers of clients just might. Most of the things that people cite as flaws of POP are really flaws in particular implementations, not in the protocol. The POP protocol is limited in scope, but I don't think this is a flaw; POP just has a different design goal. Well, that's fair. The flaw of POP are, as far as I'm concerned, that it doesn't do what I want it to do... which is provide for management of multiple mailboxes. Not it's fault, I suppose, but still a reason not to use it. ~Kyle - -- If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you. -- Don Marquis -BEGIN PGP SIGNATURE- Comment: Thank you for using encryption! iD8DBQFJwm2iBkIOoMqOI14RAvGEAKDON0+SUjXi/c4NOAXasuS55Z1lJQCg9DVj 7oZnmUx1l16zJk+1Pk3Xq6o= =eAkV -END PGP SIGNATURE-
Re: what is the benefit of imap? Another meta-question.
On 2009-03-18_21:01:38, Jan-Herbert Damm wrote: Hello, i have a meta-question. imap-issues are being discussed on this list quite frequently. i wonder what the benefit of imap generally is? if you have access to broadband flatrate internet (as many people in agglomerations here in germany do) i can't think of the benefit of managing my mails on a remote server. if you consider this question silly or off-topic please give me a hint where i could find an answer. thanks. Another meta-question, where can I find a straight-forward description of imap, without the enthusiastic pushing? What is it? Not in some narrow sense, but what is involved in 'being an imap user'? I suspect it is more complicated than the pusher would have one believe, but ... I don't know. I sense that it is useful to people who travel. Is that its main feature? -- Paul E Condon pecon...@mesanetworks.net
