On Wed, 2014-09-03 at 18:26 +0100, Pete Biggs wrote: > On Wed, 2014-09-03 at 10:22 -0600, Zan Lynx wrote: > > On 9/3/2014 5:45 AM, Pete Biggs wrote: > > > I've never heard of a problem of IMAP duplicating emails and, knowing > > > how the protocol works, I can't see how it can! > > > > The protocol won't, but servers and clients will. > > > > I've had Thunderbird (old version, now fixed) time out while copying > > large numbers of email messages from one folder to another. This > > resulted in copies of the message in both folders, because it didn't > > delete the messages until the copy was complete. > > > > I've also had the server lose delete flags on abnormal client shutdown, > > which means that messages copied to another folder get resurrected, > > resulting in two. And when the filter runs again on next client startup, > > more copies are created. > > > > So yeah, IMAP can make copies happen. > > No, IMAP can't - there's nothing in the protocol specification that > would lead to a duplication of emails. The implementation of the > protocol is a different matter - in fact the problems you mention are > totally protocol independent. Bad things can happen when using IMAP but > they aren't necessarily IMAP's fault.
Any distributed system is subject to partial failure, i.e. one part stops working or loses communication with another part. If data is in the process of being moved between the two parts when that happens, the designer has to decide between allowing data to be lost and opening the possibility of duplicating it. Systems which aim for reliability invariably choose the latter option, because the mess can always be cleaned up later. Sometimes the cleanup is automatic (e.g. transactional databases, many remote filesystems) and sometimes it's "manual" (i.e. visible to the end user). AFAIK all email systems fall into the latter category because a) it's not that big a deal, and b) doing it automatically would be complicated and could introduce other errors. poc _______________________________________________ evolution-list mailing list evolution-list@gnome.org To change your list options or unsubscribe, visit ... https://mail.gnome.org/mailman/listinfo/evolution-list
