nnimap: moving messages is unbearably slow

nnimap: moving messages is unbearably slow

[Frank Cusack]

Hi,

I'm using nnimap.  I do not have total-expire or auto-expire set; I want
messages to remain forever unless I explicitly send them away.  (I'm
thinking I might change this.)

So I expire messages I want deleted, because there are LOTS of messages
(more than 75%) I do not want to stick around forever, or even a day.
My expiry stuff looks like this:

(setq nnmail-expiry-wait-function
      (lambda (group)
        (cond ((string= group "user.frank.Trash")
                31)
              (t
                'immediate))))
(setq nnmail-expiry-target
      (lambda (group)
        (cond ((string-match "^user\\.frank\\.auto\\." group)
                'delete)
              (t
                "user.frank.Trash"))))

which works great, except that Gnus takes forever to move a message!
About a second per message.  So when leaving a mail group, I get a nice
little break before entering the next one.

I would set it up to just move expired messages when quitting, but I don't
want to have to wait forever to quit.

I would be perfectly OK with just leaving expired messages where they
are, I can always use / M E to not see them, but that only works for
Gnus.  Since Gnus doesn't set a standard flag (say, /Deleted ?) when
I go to another mailreader I get screwed.  So I pretty much have to
move the messages.  I'm not really keen on deleting them immediately
(B Del), although in the abscence of other ideas I may just do this.

I also noticed that when messages are moved to my Trash folder, they
don't keep the expired flag.  In my initial go at this, I re-mapped
the 'd' key to mark messages as expirable, and then (immediately) move
the message to the Trash.  When doing that, messages kept the E flag,
and instead of the functions above I just set nnmail-expiry-wait to 31.

Any ideas why the auto-move doesn't keep the E flag?  Seems like a bug.
There is an easy workaround, I will just set total-expire to t for
the Trash group, but I thought it was worth mentioning.

thanks
/fc