You can view all opt-outs/unsubscribes by going to Subscribers > View All > Filter > 'Opted-out'. Click Export to create a downloadable CSV of your opt-outs. Your exported file will be shown at the top right of your account within a few seconds.
To view who has opted out of a specific message, select that message and scroll down to the Message Activity. Select Opt-outs to see who opted out of texts in response to receiving that specific message.
Do you have more questions? Reach out to our team in chat! We'd love to help.