I am migrating some files and folder data to our new email server and was wondering what the best way to do this would be. I know there are several options and they all have they're advantages but I wanted to ask here and see what everyone recommended.

I have a directory called:

/var/lib/mailman/lists/ and there are many sub directories in lists/ so I want take everything that is /var/lib/mailman/lists on server_old and mirror the identical directory (already exist) on server_new.

I was told I should simply tar cvjfp /tmp/lists.tar.bz2 from the lists directory on server_old and then scp over to server_new and extract. Is this the best or can I simply use rsync or something like that?

Thanks for any suggestions!

In my opinion, rsync simplifies the process and eliminates the extra step of creating the tarball and then copying it over. You simply sync it up with the rsync command.

Will rsync also retain permissions from server_old to server_new?

Yup, you have that option with rsync.