Hi Team , I have a requirement where i have a user input task from which i have

Does this address your question?
forum.appian.com/.../Send_Email_Smart_Service

Hi Srinivasan ..Thanks for your reply but it states about the simple use of emai smart service . My requirement states that i need to send email as a part of user input task.
Hope I am clear with my question.

Right, so you want to have a button or something like that within a form that sends the email out - is that correct? In that case, you can still have the button submit the form, call email smart service and loop back to the form again (activity chaining).

Ideally, you would use Related Actions or a Quick task to perform such activities.

The last option is to write a plug-in function that does what send email smart service does but I highly recommend using out of the box facility for this.

This requirement is within the process model and not as a quick task ... so while using the approach as you just told how it would be as good as using conventional way of using email smart service for sending emails .. what i want here is if I fill few fields in user task and upload some documents there .. it should reflect in email smart service or an email like template as a part of next user input task (chained so that it shpuld be seen as a part of same task).

I'm not sure I follow your requirement. Let me playback. Are you saying that user X is going to fill in a task with the data and upload some documents and in the next task (activity chained), this user should see the content formatted as an email? Is that correct? If so, the standard form and activity chaining should achieve this.

yes .. so how the next user input task will be formatted as an email ? and how document will be populated/reflected in that user task .. ?

Well, you should design that form to look like the email and use the value saved in the first form to be populated as default value in the following form.