added sender identity note to whitelabel page
added sender identity note to whitelabel page

Whatthefoxsays/docs,ksigler7/docs,sendgrid/docs,ksigler7/docs,hardikjain29/docs,jacobmovingfwd/docs,Whatthefoxsays/docs,katieporter/docs,katieporter/docs,Whatthefoxsays/docs,jacobmovingfwd/docs,hardikjain29/docs,hardikjain29/docs,sendgrid/docs,jacobmovingfwd/docs,Aonepathan/docs,katieporter/docs,Aonepathan/docs,jacobmovingfwd/docs,hardikjain29/docs,Zaftula/docs,Aonepathan/docs,Zaftula/docs,jacobmovingfwd/docs,Zaftula/docs,Zaftula/docs,Aonepathan/docs,katieporter/docs,katieporter/docs,sendgrid/docs,hardikjain29/docs,Zaftula/docs,ksigler7/docs,Aonepathan/docs