We support bi-directional sync for email subscription status between Salesforce CRM and Mailmodo i.e., if a contact or lead is marked as unsubscribed the same will be updated in Mailmodo as part of the regular sync of contact and leads. 

Similarly, if a record is marked as unsubscribed at an account level in Mailmodo, the same will be updated in Salesforce. Currently, we don’t update subscription status in Salesforce if the user has partially unsubscribed from certain email types. 

Please note -> In order to sync and update the Email Opt Out status, please ensure "HasOptedOutEmail" must be accessible by API and visible & editable in both Contact & Lead layouts. See this article to learn more.