How to send Basic Authentication credentials in HTTP POST

You need to set the Request Headers as:

Authorization: Basic

** UsernamePassoword should be separated with a colon e.g., Username:Password and then encoded to Base64

Setting up HTTP Receive Location in 2010 & IIS7

Microsoft has changed the IIS like anything. So has the method of configuring the BizTalk HTTPReceive.dll

See the following link: http://msdn.microsoft.com/en-us/library/bb246041(BTS.10).aspx

How to convert text to Base64

There's a utility included in Fiddler that can help you convert text to any encoding format. It's the TextWizard in Fiddler that you can use to convert.