you cannot use HTTP Post in M10.
The only way of communication via M10 modem is emails.
You might be confused with IP gateway option of ORBCOMM satellites. It has nothing to do with modem.
To send an SCO to destination you can specify how your message has to be delivered. ie: via messaging gateway or via IP gateway. If messaging gateway SCO will reach you inbox via emails. If IP gateway you will have a weblink for each modem to receive this message.
This is applicable for SCT also