I don't think OpenLDAP is going to help you with setting up enterprise email services. Perhaps for authentication? Alternatives for Exchange usually go in the

I don't think OpenLDAP is going to help you with setting up enterprise email services. Perhaps for authentication? Alternatives for Exchange usually go in the direction of outsourcing (which ironically can mean: still Exchange, but not in the ball-and-chain on-prem way). Cloud options exist, but for people who for whatever reason require something to physically exist at a specific location (which is weird for email) commercial offerings are plenty (i.e. Zimbra, Zarafa, IBM's stuff, Red Hat's stuff, Oracle's Stuff).