It's possible to capture opt-out information for individual contacts to then be used for reporting purposes.
Note: If your account was created prior to February 2021, you will need to lodge a support request to have this feature enabled
When HubSpot is connected to the MessageMedia app, a custom property is automatically added to each contact record's property list, called "SMS Opt Out/In":
This field is free-form, and will allow a user to implement a workflow trigger to populate the field with information about whether the contact has opted-out from receiving SMS Messages by means of a reply containing an Opt-out keyword.
Configuring the workflow
Begin by setting the trigger as SMS opt-out received, with an occurrence set after the date on which you want the workflow to become active:
Next, add an action and select "Set Property Value" from the Property management option list:
From the resulting menu, select the "SMS Opt Out/In" field:
Next, enter a value with which to populate this field (e.g. "Opted out") when the trigger conditions are met:
Save your action, and your workflow is ready to be applied.
The inbound opt-out message can be unsolicited, provided that the number of the opt-out message sender is stored on the contact record in E.164 format. Otherwise, the opt out must be a solicited opt out (i.e. a reply to an outbound message) where the outbound message was sent from within SMS for HubSpot. This excludes opt-out replies to messages sent via the MessageMedia web portal account associated with the HubSpot extension, or non-reply (unsolicited) opt-outs sent to a dedicated number in the MessageMedia web portal.
You can then use the "SMS Opt Out/In" property as a filter to run reports, and see which of your contacts have opted out to your broadcasts.