How to use package from community-testing

Hi, I am running arch-linux with cyrus-imapd as mail server for several years and now cyrus-imapd appeared in community-testing. I am planning upgrade and switch from cyrus-imapd aur package to version from community-testing. What is a recommended way to test only this package? If I enable community-testing in pacman.conf, then doing pacman -Su will still pull official packages from community until I explicitly request a version from testing? Regards, Łukasz