imap servers

While doing preliminary work to retiring a legacy proprietary email system, my own, looking at maybe setting up an IMAP server, just for the fun of it. On a fresh openSuse 15.4 I see none installed by default and when I go sniffing about in YAST, i find several flavors available for install: dovecot dovecot23 imap (and sundry) Funny I was just ready about 3 body problems . . .