A simple worker service with event bus proxy to send emails.
An email can be sent in the format:
{
"from": "from.email@address",
"to": ["toaddress1@something.com", "toaddress2@something.com"],
"cc": ["ccaddress1@something.com", "ccaddress2@something.com"],
"bcc": ["bccaddress1@something.com", "bccaddress2@something.com"],
"subject": "This is a subject",
"body": "This is a body",
"contentType": "text/plain"
}