Oneliner PowerCLI-
Powercli script to get ESXi hosts connection state such as Host disconnected or nonresponding.
Get-VMHost |Where{$_.ConnectionState -eq ‘Disconnected’} |Select Name, ConnectionState
You can also try below to send output to mail.
Send-MailMessage -from ‘mail@.test..com’ -to “mail@.test.com.com’ -Subject ‘Report’ -smtpserver ‘smtp server’