sendgrid/sendgrid-csharp — pull request #5 by bobmclaren (2012-06-01 02:40:45+00:00)
Title: AddTo functionality added to the IHeader and Header classes

I found that I needed a way to add the "to:" array to the X-SMTPAPI header, so I made a quick update, as discussed here:
http://community.sendgrid.com/sendgrid/topics/multiple_recipients_with_the_net_api_library