[Dovecot] POP - preventing re-download with server move

[Trutwin, Joshua]

Hi,

Curious if anyone has any good suggestions to handle this.

I try to get my hosting users to use IMAP but most use Outhouse and
the IMAP support is somewhat annoying for many so I typically have
them change their settings when using POP to leave copies on the
server.  That way when they get the inevitable virus or wanna use
webmail they have a backup copy and webmail sees their saved mail.

So now I have to move my sites to a new server and I'm trying to
avoid having all these messages re-downloaded by POP clients.  Some
of the sites I've moved with low email usage have just dealt with the
re-download and cleaned up afterwards.  I have a few other accounts
though that I'm more concerned about that have massive amounts of
stored email.

The mail is stored in Maildirs - a sample file: 1280409166.23580.foo:2,S

If I move this to server "bar" would renaming the file to
1280409166.23580.bar:2,S prevent this somehow?

Old server uses qmail-pop, new server uses dovecot 2.0.

Thanks for any tips,

Josh