Let me clarify a few things:
There are Transactional emails meaning, the emails that will be sent out from your server.
The default emails like registration, forgot password etc will not be sent if you are using Vultr and GCE. It is because the port 25 is blocked by the respective provider. You need to set up an SMTP service and/or contact the live chat support.
The one you are talking about is, Email hosting. Cloudways is a bit different from shared hosting/cPanel that provides you Email hosting too. However, it is always recommended to keep emails and hosting separately. You can Google the WHY factor
At Cloudways, we are partnered with Rackspace to provide email hosting. You can get it in just $1/email/month instead of $2/email/month (official price by Rackspace).
However, if you are looking for a free email hosting service. You can set up Zoho mail on Cloudways.