Add SMTP Integration warning
Add SMTP Integration warning

* Updated /Integrate/index.html with a warning discouraging users from pointing email traffic to one specific IP address instead of smtp.sendgrid.net
sendgrid/docs,jacobmovingfwd/docs,Aonepathan/docs,Aonepathan/docs,jacobmovingfwd/docs,jacobmovingfwd/docs,hardikjain29/docs,Aonepathan/docs,hardikjain29/docs,Zaftula/docs,Aonepathan/docs,katieporter/docs,sendgrid/docs,Zaftula/docs,ksigler7/docs,hardikjain29/docs,hardikjain29/docs,Zaftula/docs,Whatthefoxsays/docs,Whatthefoxsays/docs,ksigler7/docs,hardikjain29/docs,Aonepathan/docs,Whatthefoxsays/docs,Zaftula/docs,katieporter/docs,katieporter/docs,jacobmovingfwd/docs,jacobmovingfwd/docs,ksigler7/docs,katieporter/docs,katieporter/docs,sendgrid/docs,Zaftula/docs