Hi Prathish,
You can check the settings in transaction SICF to ensure that these are defined correctly.
You could also try temporarily changing to use SAPHTTP instead of the HTTP plugin to see if different errors are reported to provide you with more information.
To do this; create the following entry in the SDOKPROF table in SE16:
NAME: USEHTTPPLG
VALUE: OFF
Leave all remaining fields blank and save your changes.
Regards,
David