> Actually people saying mbox is a bad database are in principle right > (I never liked maildir either: dumping metadata into file names seemed > to me a bit disgusting too, but I disgress). But there's something > special about mail databases which eases that a bit: records (i.e. > mails) are *mostly* immutable (save for some metadata), so cleverly > written libs (mutt, dovecot) can be suprisingly good despite all.
Actually, I think the reason it works is unrelated: it's just that people have put enough engineering efforts into making it work for large mailboxes despite its inadequate format. Caching, auxiliary indexes, batched-rewrites, etc... can go a long way. Stefan