New line characters in message body.

["Maruvada, Suryakiran" <smaruvada@xxxxxxxxxx>]

Hi,

 

When I give echo "first line \n second line \n" the out put is 

first line 
second line

but when I use the same with mutt i.e
echo "first line \n second line \n" | mutt -a <<attachment>> <<mail-id>>
my body of the mail come like :   "first line \n second line \n"

Can any one suggest me what was wrong. How else I can avoid \n in the
subject line. I want my body in multiple lines

Thanks and Regards,
Surya Kiran