Unsubscribe/Email Preferences

There are several approaches I see out there when it comes to email/notification/messaging preferences. My question is what approaches and features are most useful?

• Specify preference as to the type of Email they want to recieve (Promotional Emails, New Feature announcement, weekly digest, user invitations, etc..) My organization we have 11 different categories of emails that we send out.
• The frequency of receiving Emails (How often do you want to receive an email? (ex. Get one email with the best information every 30 days...)
• Delivery Type (Get it as an SMS message, Push notification, FB Messenger Message, Email, etc.)
• Unsubscribe All (the surefire method of getting rid of all communication)

The most difficult is with the features what is the level of granularity? The simple approach of one setting that applies to all the types, or do we allow a frequency and delivery method preference on each type? That's when it starts to get messy. Are there any studies done on this?