It is only possible to receive ‘replies’ when sending from a mobile number (shared or dedicated). Message sent using using a ‘name’ or ‘non mobile number’ as the ID cannot be replied to, as such they are ‘one-way’ only.
Note: when adding your personal mobile number as the ‘from’ number (this is a Custom ID) message replies will be delivered back to your personal handset. Only numbers supplied by Cellcast (dedicated numbers) can receive message replies back to Cellcast.