Customized Join Replies
When a phone number joins your contacts by texting in from their phone, you have the option to set up a text message to be sent back to them automatically. This can be set up for the entire account and/or for specific groups in your contacts.
The maximum length for your auto-reply is 160 characters. If you are on the Pay As You Go plan, your account will be deducted 1 credit for each custom auto reply that is sent.
To enable a custom auto reply for the entire account, visit the Settings section, select Text Settings, and choose Edit next to "Enable Join Reply?" where you can select the enable the feature and type out a custom message.
To enable a custom auto reply for one of your groups, visit the Contacts section, click on the group name, select the edit icon, choose to edit Enable Group Join Reply where you can type out a message when contacts join that group. You also have the option to assign your group a keyword. This would allow individuals to join the group by texting "join [group name]" or "join [group keyword]."