Yes, a full time exchange admin.
If you've never seen a need for a full-time Exchange admin, you've probably never seen an enterprise network where Exchange servers operate under extremely heavy load, serving thousands of employees, utilizing a significant majority of the capabilities of the Exchange server "product" and a few third-party options besides. I have. It's not a pretty sight, and a full-time Exchange admin is definitely required to ensure reasonable uptime and performance.
Keep Up with TechRepublic