- Plesk 12.5 for Windows
How to configure MailEnable on Google Cloud Platform?
According to official Google CloudPlatform Documentation Google Compute Engine does not allow outbound connections on ports 25, 465, and 587 .
As it is described in MailEnable KB #ME020014 there is an workaround how to configure sending mail through some SMTP relay server even if port 25 is closed:
Within the Administration Program, under the properties of the SMTP Connector, select the Smart Host tab and configure the properties of your ISPs SMTP Server. This will forward all outbound mail through their SMTP Server (which will in turn deliver it to the destination mail server).
In case of any issues contact Google CloudPlatform Support