> Does #1 mean that there are IMAP servers where my phone and my desktop and my laptop (etc.) can't all read my mail simultaneously? [edited] I believe that's

> Does #1 mean that there are IMAP servers where my phone and my desktop and my laptop (etc.) can't all read my mail simultaneously? [edited] I believe that's the case. The ancient and venerable UW implementation of the ancient, venerable, and awful Unix "mbox" format from the UW server has a lot of these sorts of problems. The UW server did not have this problem with some of the other formats. It suffered a lot from supporting a lot of different formats in borderline hostile conditions (i.e., users were assumed to have filesystem access to the server so no improvement to locking or caching was practical). None of the current commercial implementations suffer from this, but I suppose I can say that the lowest common denominator is still pretty low. I may be overstating this because what I'm describing would also outlaw message delivery, which I don't think is the case. I think one of the formats did have problems with trivial concurrent access but I was never a UW-imapd expert. I am sure that the mbox format has problems with EXPUNGE (removing messages flagged deleted) as well as many other issues. I guess it's also worth reiterating that STATUSing a SELECTed mailbox (one that's open in another connection) is a pretty big waste of server resources, as someone else noted.