On Wed, 30 Jan 2003, Timo Sirainen wrote: > I guess it would be possible to create GLOBAL-UIDVALIDITY which would > guarantee that guidval+uid would uniquely identify the message within > the user's all mails. > > Except how do you guarantee it's uniqueness? Think shared folders for > example. It would really have to be global among all users, which could > be pretty difficult to implement safely.
That's the real issue. UIDVALIDITY is a 32-bit value, which is much too small for any globally-unique mechanism unless you have some sort of central UID issuing authority. In the absense of such an authority, you need more bits. I think that 48 bits is probably the minimum for global uniqueness for self-assigned UIDs, and 64 bits would be better. -- Mark -- http://staff.washington.edu/mrc Science does not emerge from voting, party politics, or public debate.
