[exim] Moving a queue to another server

Hi,

I am wondering if there is a good way to move all pending mails from
one exim server to another.
It is probably not the best idea to move the files from one spool
directory to another (idea 1).
I found this exim option in the man page and I guess it would be
possible to build a separate transport for transfering the queued
mails (idea 2):
exim -MC <transport> <hostname> <sequence number> <message id>
Another idea (3) would be to use the "fallback_hosts" option for each
transport and trigger an new delivery attempt for every mail in the
queue.
Idea 2 and 3 would reset the retry time and add another received
header, this would (probably) not be a problem.
I'd like to avoid canceling the delivery with -Mg.

Any advice on how to approach this mest?

Greetings,
Christian