mailing list message delays

[Jed Brown]

I observe that some messages from the PETSc lists (both -users and
-dev) are delivered immediately and some are delivered around an hour
late.  This can be somewhat confusing when messages come wildly out of
order and occasionally leads to redundant responses.  I haven't
noticed any logic as to which messages are delayed.  While strict
order-preservation is obviously not possible, is there anything that
can be done (easily, don't waste time on it) about the huge seemingly
random delays?  (I don't see this behavior from any other lists.)

Jed