# Managing group subscribers

If you want to automate certain actions, like opt in / opt out responses, you can easily do this with Flow Builder; you can learn how to set this specific flow [here](https://support.messagebird.com/hc/en-us/articles/360000358457-How-to-set-up-opt-in-opt-out-automatic-SMS-subscriptions). 

**Opt out**

When sending out a campaign, make sure your contacts are in a group.

If you configure a rule like the one shown below, those users who reply ‘Stop’ will be automatically removed from the group specified:

<figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-ba61c9b4537d70a7ab361518e7ced79a994e33c6%2FScreen_Shot_2017-12-20_at_10.34.51.png?alt=media" alt=""><figcaption></figcaption></figure>

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This will remove the contacts from the group, but they will remain in your address book.

**Opt in**

You can also create multiple flows for one Number, allowing you to trigger different actions depending on pre-specified keywords within the response of the user.

A company could use this to keep track of customers who are interested in a certain offer. For example: if you send ‘Reply SPA to enter our prize draw’, and want to keep all the replies for this offer in one place, you can set up something like this:\ <br>

<figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-968fca5dc2f35355c1181ffc9d64c9dc59b34c4a%2FScreen_Shot_2017-12-20_at_11.15.49.png?alt=media" alt=""><figcaption></figcaption></figure>

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The relevant replies would be automatically forwarded to a phone, email or added to a group, or you could even configure an automatic response.<br>

There is no limit to how many contacts can send you to opt in or opt out responses