Each recipient address must be separated by a comma when configuring email notifications for VMware vCenter Server alarms.
When an alarm configured to send an email notification to multiple recipients is triggered, you experience these symptoms:
VMware vCenter Server 6.0.x
This issue occurs when a semi-colon is used to separate each email recipient. The VMware vSphere Client user interface display each recipient value separated by a semi-colon. In the VMware vSphere Web Client, each recipient is separated by a comma.
When configuring email notifications for VMware vCenter Server alarms, each recipient address must be separated by a comma. Using any other delimiter may cause the notification email to fail.