Is there a way to send an Http Post with an atachment to a restful web service?.

If you already have a custom smart service working then it's fine to keep using it. You can eventually switch to the out of the box HTTP Query once it has additional features that your plug-in doesn't support (e.g. NTLM support, etc)

If you already have a custom smart service working then it's fine to keep using it. You can eventually switch to the out of the box HTTP Query once it has additional features that your plug-in doesn't support (e.g. NTLM support, etc)