When creating a group, you may find it useful to enable the opt-in required message. This will prompt users to respond ‘Y’ to confirm their subscription or they can enter an email address. The user must respond to this message in order to receive join message and continue receiving future messages. It can be used to gather more data from subscribers, and to stop fake numbers from opting-in.
How to Set Up a Double Opt-In
Go to Groups & Keywords.
Either select/edit an existing group or create a new one.
Under Advanced Features, check the Enable double opt-in box to enable a double opt-in.
Select an Opt-in type.