Applicable to End Users
When you use Mobile Capture on an iOS to send SMS texts to other iOS users, you might receive replies as iMessages and not on Mobile Capture. This behavior occurs due to an iPhone limitation.
Limitation
iPhone connects various contact numbers of a contact to a single entry and bundles replies. Consider the following scenario:
Susan, a Mobile Capture user on iPhone, has two contact numbers:
Personal Mobile +1-818-483-0902
Enterprise Number +1-617-562-4089
Lisa, a client, who is using an iPhone has saved Susan's personal number and enterprise number. Lisa's iPhone bundles both numbers of Susan into a single contact.

Both Susan and Lisa have enabled iMessage on their iPhones.
Issue
When Susan sends a text message from Mobile Capture on her iPhone to her client Lisa, one of the following can occur:
If Susan and Lisa had not exchanged iMessages earlier, a new SMS thread is created.

If Susan and Lisa had previously exchanged iMessages, the text message from Susan is received as an iMessage. All further communication is continued as iMessage.

Workaround
Since this is an iPhone limitation, the Mobile Capture user can request the person they are communication with to do one of the following:
Delete and replace the Personal Mobile number of the Mobile Capture user in their Contacts list with the enterprise number.
Create a separate contact for the Mobile Capture user with the enterprise number.