Can I change a Support Reps e-mail address?
Certainly, a Support Agents email address can be changed. However, it has to be changed by the individual Support Agent only.
To change the e-mail address, Goto Setup > Personal Settings > My Zoho Account > Click Email Address, add new e-mail ID. This would send a confirmation e-mail to the newly entered E-mail address.
On confirmation, you can login back again to My Zoho Account and make the new Email ID as your primary ID.