--On Monday, February 13, 2017 13:48 -0500 Ted Lemon
<mellon(_at_)fugue(_dot_)com> wrote:
The model of IMAP is that:
* Each message resides in a single mailbox,
* Each message has a set of independent flags,
* Each message is immutable.
This would be unfortunate. The "mailbox" paradigm really
doesn't work well—as someone mentioned earlier in this
thread, it makes synchronization needlessly slow and painful,
and it also restricts the end user's ability to tag messages
with more than one meaning.
Just a clarification in the hope of understanding where we
disagree...
I would have described the IMAP model as assuming that each
message is associated with a single mailbox. Most of the issues
you mention are associated with "resides". Up to a point, it is
possible to use a Google-like arrangement to support all of the
IMAP functionality I can think of simply by attaching a label or
attribute with the mailbox name and constraining retrievals,
searches, and displays accordingly. That is exactly what at
least some of the systems that use a Relational DBMS as a
mailstore do, whether they then have "relation per user" or
treat the UserID as yet another attribute.
That may not be the best thing to do and may or may not provide
equivalent functionality and efficiency for various operations.
In particular, it still implies some advantages for having all
of the messages associated with a given mailbox on the same host
or closely-related set of hosts and I have no idea whether gmail
does that or not. But, if one goes much past that, my earlier
comments about a switch in reference models and fundamental
architecture apply.
john