Customer Service Mass Email Type

On occasions it is necessary to send an email to all clients which I think should be considered under "performance of a contract".

Here I am thinking emails like:

 

i) Commmunicating scheduled outages
ii) Updates to Terms of Service

Right now, as far as I can tell the only mass email type that can be sent is a Marketing Email. If I have customers that have unsubscribed from Marketing emails, they won't receive what are IMPORTANT emails in relation to the performance of our contract with them.

As such, when creating en email, you should be able to create with a Subscription Type = Customer Service. If clients want to unscubscribe from these emails they should be able to do so, but they shouldn't be unsubscribed from them because they don't want info about upcoming product launches etc.