Provide the ability to set the extended properties on reactive emails in the same way they are available in traditional. There is currently no way to set extended properties on reactive emails, this currently means we will have technical debt in maintaining an secondary application purely to send emails to enable setting importance, out of office suppression, expiry etc 

The following is an example of the traditional extended properties in a traditional email

The above is used to suppress out of office messages for mailings and prevents a deluge of out of office responses when a number of emails are sent.

Importance is set on some emails based on the business process being followed e.g. high risk/value the importance can be set to High and the email client shows the importance of the email.

The extended properties on the email has solved a number of issues with email visibility in a users inbox by adding the relevant property e.g. importance, sensitivity and also expiry has meant that processes that do rely on an email get the relevant attention required.