Can I copy email folders to my new MacBook air and also keep a copy of the email folders of the original MacBook Air computer

Can I migrate all email folders from my old iMac to my new MacBook Air and also keep a copy of the same email folders on the original iMac? I am leaving the old iMac at my office, from which I am retiring, and want to migrate the entire contents to my new MacBook Air. However, I would like to keep the emails on the iMac for my successor to access them.