On Tue 24 Nov 2020 at 17:17:24 (+0000), Curt wrote: > On 2020-11-23, rhkra...@gmail.com <rhkra...@gmail.com> wrote: > > On Monday, November 23, 2020 06:15:09 AM Sven Hartge wrote: > >> Joe <j...@jretrading.com> wrote: > >> > That's why we have IMAP, which doesn't use mbox. > >> > >> The IMAP protocal and the backend storage have no connection. ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑ > > > > Well, they do in a way -- if you use IMAP from your ISP for example, you > > don't > > need local storage on your email device (not any of mbox, maildir, or > > whatever). > > > > (I don't use IMAP (I use POP3), but I assume that if I were using IMAP as > > described, I could save emails on my local device, but I'm not clear on > > that > > mechanism / storage method.) > > The IMAP protocol and the local storage format are orthogonal, I believe is > what > he said, so you've come full circle in your reflections.
AIUI the backend storage is what the IMAP (and POP) protocols serve, and the local storage is where the emails are stored when they have been served. It appears that the OP, like me, has their emails served by a remote server, so one typically has no control over, knowledge or concern about the hosting service's backend storage (beyond its being reliable, 24/7 available, etc). There's a big difference between the requirements for your local storage when using POP compared with IMAP. When using POP in a conventional manner (transfer, and delete at the server end), you need reliable local storage. And you also need reliable file locking at least when you're using mbox files. OTOH for IMAP, there's no requirement for any local storage at all, beyond a screen display so that you can read the emails. The client *can* cache emails and/or make local copies, but it's not necessary because you can reacquire any email at will. Joe's IMAP *server* does have backend storage, but it looks as though that's being fed by SMTP, which AIUI is not what the OP is thinking of using (nor me). Cheers, David.