SQL Server :: Send Storedprocedure Results As Email Body

I have 3 procedures.

1. SP_General - Gives the output with 3 columns like: ID NAME DOB with multiple rows

2. SP_HTML - Gives the HTML formatted output like: <table><tr><td>ID</td><td>NAME</td><td>DOB</td></tr></table>

3. SP_Email - Sends email (written by using extended stored procedures). Input parameters: Body, etc

When I DO:

1. EXEC SP_Email @Body = 'Hello this is testing'. I recieve the email saying: Hello this is testing

2. EXEC @Results = SP_General

EXEC SP_Email @Body = @Results. I recieve the email saying: 0

3. SELECT @Results = EXEC SP_HTML

EXEC SP_Email @Body = @Results. I recieve the email saying: 0

4. SELECT @Results = '<table><tr><td>ID</td><td>NAME</td><td>DOB</td></tr></table>' (If hardcoded like this)

EXEC SP_Email @Body = @Results. I recieve the email with correct output in a nice formatted table: ID NAME DOB

Its working in 1 and 4 cases but not 2 and 3. As I cannot hardcode like that, can anyone tell me where I'm doing mistake in 2 or 3 cases?