Folks, over in #notmuch, we just floated an idea that I'd like to get out to you. We've been debating storing tags for messages. Therefore I am cross-posting. Please forgive me. So far, there are two approaches: 1. External database, which has the downside of not being synchronisable with standard IMAP, like the rest of your mail (assuming you use IMAP). Also, it's possible for mailstore and database to get out of sync. 2. In-headers, which has the downside of leaking (e.g. when bouncing), and incurs the risks associated with message rewrites (which I think is pretty much ignorable, but it's still there). Also, there's a performance issue, but in the context of an indexer like notmuch, this is negligible. The leakage is real, though and I think it makes in-headers unusable. After all, I don't ever want anyone else to know that I tag e-mails from my boss as "from-idiots", and I forward and bounce mail on a regular basis. I could tell my MTA to remove those headers, but I might forget to do that on a new system. We also previously determined that IMAP keywords are pretty much useless as they are stored per mailbox, not per message, not standardised, and limited in their length anyway [0]. This also means that we don't really need to investigate sensibly storing tags in Maildir (e.g. with xattrs), because IMAP cannot transport them. 0. http://lists.madduck.net/pipermail/mailtags/2007-August/msg00016.html Seriously, who implemented IMAPv4rev1 and what sort of crack were they smoking?? I remember there was some KDE groupware contacts manager that used IMAP to synchronise contacts. At first, this sounds horrible, but when you detach IMAP from RFC822, it becomes a generic synchronising protocol. The next step is then straight forward, and I want to share this idea with you: How about using pseudo-mails stored in Maildir and synchronised by IMAP? E.g. every folder could have a subfolder .TAGS and if we find a way to smartly pair messages between parent and subfolder, we'd have a tag store alongside the mailstore it refers to, but without the danger of leakage, and without having to rewrite messages. The major problem with this is when clients don't understand this "protocol", for then they will display all .TAGS folders as regular IMAP folders, and try to treat the messages therein as regular mails. Somewhere sometime this is bound to blow up and I don't really know how to prevent that. Anyway, the idea is out now. Thoughts? -- martin | http://madduck.net/ | http://two.sentenc.es/ echo Prpv a\'rfg cnf har cvcr | tr Pacfghnrvp Cnpstuaeic spamtraps: madduck.bogus@madduck.net