SQL Server Error: Only functions and some extended stored procedures can be executed from within a function.

Hi, On executing a function return below error

Msg 557, Level 16, State 2, Line 1 Only functions and some extended stored procedures can be executed from within a function. 

Create procedure [dbo].[sp_EmailCHk] (@email varchar(100))
as
insert into dbo.Email(Email_Email) values(@email)

GO

CREATE function [dbo].[fn_ChkEmail]
(
    @email varchar(2000)
)
returns int
AS
begin
      declare @status varchar(1)
      SELECT @status = count(*) from Email where Email_Email=@email
      if @status=0     
      begin
            exec sp_EmailCHK @email
      end
      return (select @status)
end

GO

select [dbo].[fn_ChkEmail] ('useremail@gmail.com')