It is possible to email from the cloud. The trial does not support this functionality, but hosted apps in the cloud are supported.
Please contact support via the support portal to get access to the email server you want to use.
You need to have your own email server to send emails with. Mendix does not provide one with the Cloud server as of this time.
Note you probably need a firewall exception to connect to your SMTP server from the Mendix cloud server.