I have configured a vSphere 5.5 environment using the vcenter appliance and am trying to setup alerts. The alerts are being triggered and logged by vcenter but no emails are actually being sent. We created an account in AD with a specific email address and I have specified vcenter to use that address to send to. I'm not sure what I'm missing as I have specified the smtp server in vcenter. I found this KB article but I'm not sure this applies: