[grace-baker Hexnode 26 November 2019 grace-baker Moderator]

Of course Liam! We are here to help you.

Yes, Hexnode can block outgoing messages on Android devices.
Please navigate to Android–>Advanced Restriction–>Allow Account Settings–>SMS. Beneath the SMS there will be two options listed:
Receive messages: Allow/Disallow incoming SMS text messages.
Send messages: Allow/Disallow outgoing SMS text messages.
Please uncheck the box corresponding to ‘Send Messages’ to block outgoing messages on the devices.

Kindly use the link for a reference.

PS: The feature is supported only on Samsung Knox devices.

Cheers!
Grace Baker
Hexnode MDM